Office of Strategic Services - Reports - Celebes Sea Area- Volume 1, May 1944

PSF subject file ; OSS Celebes Sea area may 1944 OFFICE OF STRATEGIC SERVICES WASHINGTON, D.C. 26 July 1944 Miss Grace Tully, The White House, Washington, D. C. Dear Grace: Would you be kind enough to place the attached memorandum before the President? Thank you. Sincerely, Pill William J. Donovan, Director REGRADED UNCLASSIFIED OFFICE OF STRATEGIC SERVICES WASHINGTON, D.C. 26 July 1944 MEMORANDUM FOR THE PRESIDENT I believe you may be interested to receive the attached copy of the JANIS (Joint Army-Navy In- telligence Study) of the Celebes Sea Area which rep- resents the successful combined effort of several governmental agencies. William J. Donovan Director REGRADED UNCLASSIFIED CONFIDENTIAL JANIS 155 Volume No. 1 of 4 Non-registered JOINT ARMY- NAVY INTELLIGENCE STUDY OF Celebes Sea Area * JOINT INTELLIGENCE STUDY PUBLISHING BOARD May . 1944 DECLASSIFIED By Authority of JCS letter, 7-25-75 By SR Date JUL 31 1975 1034 CONNECTICUT AVE. Washington 6, D. C. 30 May 1944. MEMORANDUM Subject: JANIS No. 155. 1. Joint Army-Navy Intelligence Study of Celebes Sea Area {JANIS No. 155) is promulgated herewith. 2. This is a confidential non-registered publication. It con- tains information affecting the national defense of the United States within the meaning of the Espionage Act, 50, U.S.C. 31 and 32, as amended. Its transmission or the revelation of its.contents to an unauthorized person is prohibited by law. 3. When complete, JANIS No. 155 will comprise Chapters I to XIII, inclusive, and a Plans Pouch containing reference maps. 4. As & means of effecting quick distribution, the various chap- ters will be issued as they come from the printer, not necessarily in numerical order. 5. At the time of this distribution the following chapters are issued: III, V, IX, X and XI. 6. It is anticipated that the issue will be complete by 30 June 1944. As the several chapters are received, the recipient should arrange them in numerical order in the binders provided, and check-off in the space below. 7. The effective pages of each chapter are listed inside the chapter covers. A list of the plans is issued with the Plans Pouch. A. combined List of Effective Pages will be included with the final distribu- tion. 8. The distribution of this publication to naval activities is effected through the Registered Publications Issuing Offices, and requests for copies not included in Registered Publication Allowance Tables should be addressed to the Division of Naval Intelligence. The War Department will distribute this publication to army units, and requests from army units should be directed through army channels. JOINT INTELLIGENCE STUDY PUBLISHING BOARD Chapter III VI VII VIII IX XII XIII Plans Date Rec'd JANIS 155 1 Non-registered CHAPTER I MIDWAY IS. HAWAIIAN IS HONOLULU' WAKE L MARIANAS , IS. JOHNSTON I, PHILIPPINE FRENCH-INDO IS. GUAM CHINA PALAU MARSHALL DIS. CAROLINE ISLANDS GRBERT IS / BORNEO CHRISTMAS 1. CLIEN NEW GUINEA OLOMON IS, TIMOR AUSTRALIA JOINT ARMY-NAVY INTELLIGENCE STUDY OF CELEBES SEA AREA BRIEF DECLASSIFIED By Authority of MAY 1944 JCS letter, 7-25-75 By 8R Date JUL 31 1975 NECLASSIFIED By Authority of JCS letter, 7-25-75 By SR Date JUL 31 1975 List of Effective Pages, Chapter I CHANGE IN Sunjact MATTER Erract PAGE NUMBERS Cover Page Original unnumbered List of Effective Pages and Table of Contents, Chapter I (inside front cover) Original unnumbered Text and Figures Original PP. I-1 to I-26 Figure (insert, reverse blank) Original Figure I-1 Figure (insert, reverse blank) Original Figure I-2 Figure (insert, reverse blank) Original Figure I-3 Figure (insert, reverse blank) Original Figure I-4 Text Original pp. I-27 to I-28 Figure (insert, reverse blank) Original Figure I-5 Figure (insert, reverse blank) Original Figure I-6 Text Original PP. I-29 to I-42 Figure (insert, reverse blank) Original Figure I-7 Figure (insert, reverse blank) Original Figure I-8 Figure (insert, reverse blank) Original Figure I-9 Figure (insert, reverse blank) Original Figure I-10 Figure (insert, reverse blank) Original Figure I-11 Figure (insert, reverse blank) Original Figure I-12 Table of Contents, cont'd (inside back cover, reverse blank) Original unnumbered Table of Contents Note: This Chapter is based on material available in Washington, D. C. on 25 April 1944. Page Pay FOREWORD I-1 E. Northeast Borneo I-13 I - 1 (1) Coasts 1-13 MAP EVALUATION (2) Landing beaches I-14 10. MILITARY GEOGRAPHY I - 3 F. Northern Celebes sector I-14 A. Relief I- 6 (1) Coasts I-14 (2) Landing beaches I-14 B. Drainage and water supply I - 6 (1) Rivers I - 6 13. WEATHER AND CLIMATE I-14 (2) Swamps I- 7 (3) Lakes I 7 A. Ground operations I-15 (4) Water supply I- 7 B. Air operations 15 C. Vegetation I - 7 C. Naval and amphibious operations I-15 D. Soil trafficability I- 7 D. Chemical warfare I-15 E. Critical areas I- 8 14. TOWNS AND PORT FACILITIES I-15 (1) Kaoe Bay Region, Halmahera 8 (2) Bukidnon Uplands, Mindanao I 8 A. Halmahera sector I-15 (3) Tarakan, Borneo 8 (1) Ternate I-15 (4) Minahasa Region, Celebes 8 (2) Villages I-16 F. Routes to critical areas I- 8 B. Sangihe-Talaud sector I-16 (1) Routes to Kaoe Bay Region, Halmahera I 8 C. Mindanao sector I-16 (2) Routes to Bukidnon Uplands, Mindanao 8 (3) Routes to and in Northeast Borneo (1) Surigao -16 8 (2) CAgayan I-17 (4) Routes in Northern Celebes I 8 (3) Iligan I-17 G. Regional summary I- 8 (4) Misamis 17 11. OCEANOGRAPHY I-11 (5) Oroquieta 18 A. Tides 11 (6) Zamboanga 18 B. General circulation (7) Cotabato I-18 I-11 C. Sea and swell (8) Davao 15 I-11 D. Sea-water characteristics (9) Malaybalay 19 I-11 E. Bottom sediments (10) Dansalan 19 I-11 (11) Villages I-19 12. COASTS AND LANDING BEACHES I-11 D. Sulu Archipelago I-21 A. Halmahera sector I-11 (1) Jolo I-21 (1) Coasts I-11 (2) Villages 22 (2) Landing beaches I-12 E. Northeast Borneo I-22 B. Sangihe-Talaud sector I-12 (1) Jesselton 22 (1) Coasts 1-12 (2) Sandakan I - 23 (2) Landing beaches I-12 (3) Lingkas 23 C. Mindanao sector I-12 (4) Villages 24 (1) Coasts I-12 (2) Landing beaches F. Northern Celebes sector I-24 13 (1) Manado 24 D. Sulu Archipelago and Basilan Island I-13 (2) Gorontalo 1-24 (1) Coasts 13 (3) Tondano I 24 (2) Landing beaches I-13 (4) Villages 24 FOREWORD Page I I The purpose of this study is "to make available one publication containing all the necessary detailed information upon which may be based a war plan for military operations" in the Celebes Sea Area. In order to increase the usefulness of the study, the material has been presented in 2 distinct patterns. Chapter I, entitled "Brief," is a condensation, and to some degree an interpretation, of the material presented in much greater detail in the succeeding chapters. It is intended as a "quick look," complementing the main body of the study, to which reference can be made where more detailed information is desired. The material for this study has been contributed by the intelligence agencies authoritative in the various subjects. For the purpose of convenience, contents have been made up into 4 volumes, the last of which is a Plans Pouch containing plans numbered 1 to 62 inclusive. JOINT INTELLIGENCE STUDY PUBLISHING BOARD Map Evaluation G. Geologic Map of Jembongan-Tembelang, 1:50,000. Sara- wak Oilfields, Ltd., 1936. Detail is dense. Corrects errors in existing published maps. British North Borneo A. District Road Development Maps, 1:63,360. Surveyor Gen- Netherlands Borneo eral, Jesselton. Sandakan District, 1934. A. Sangkoelirang Area, 1:100,000. NNVPM. 1934. Lahad Datu District, 1934. Tawau District, 1934. This is an oil company map made from reconnaissance sur- Kudar District, 1934. veys. No topography is shown. Geologic data is shown. Only the Maps contain general road classification. Topography is main rivers are shown in detail. All other data is sparse. Map is shown by sparse hachures. Drainage and cultural detail is considered fairly reliable. sparse. Considered to be of reconnaissance nature and of value B. Tarakan Island, 1:50,000. Topografische Dienst, 1936. for classifications but not for positions of all detail. Standard Dutch topographic map. Map is considered reliable. B. District Maps, 1:63,360. Surveyor General, Jesselton. C. Zuider Costerafdeeling van Borneo, 1:750,000. Topo- Labuk District (undated). graphische Inrichting, 1913. Simporna, 1935. Sandakan (undated). Four-sheet general map covering all of Eastern Netherlands These maps show very sparse topographic hachures and drain- Borneo. Topography is by hachures. Map is considered fairly reliable, age data. Road classification is detailed. The maps are considered to be sketchy in nature and are fairly reliable. C. District Plans. Surveyor General, Jesselton. Celebes Jembongan Island, 1 inch - 20 chains (undated) (covers parts of north and south shore). Tungku, 1:12,232, 1932. A. Noord en Midden Celebes, 1:500,000. Topographische In- Kudat, 1:15,840, 1936. richting, 1919. Tambisan, 1 inch - 16 chains (undated). Lahad Datu, 1:12,232 and 1:15,840, 1932-34. Four-sheet map covering nearly all of Celebes. Topography Tawau, 1:12,232, 1941. by hachures. Not considered reliable. Sandakan, 1:12,232 and 1:12,840, 1933-38. B. Zuidoost Celebes, 1:500,000. Topographische Inrichting, Contains detailed plans of all plantations and roads. Topog- 1924. raphy is shown by sparse hachures. Considered reliable. Topography shown by shading. Map is considered fairly re- D. Kudat and Marudu Bay, 1:126,720 (undated). Surveyor liable. General, Jesselton. C. Geologische Schetakaart van den Noordaim van Celebes, Topography is sparse and is shown by hachures. Cultural and 1:200,000. Jaarbock van het Mijnwezon in N.I., 1928. drainage detail is very sparse. Map is considered to be fairly re- liable. Reconnaissance geologic map with contours. Considered fairly reliable. E Plan of a portion of the East Coast of North Borneo, D. Netherlands Indies, 1:200,000. Topografische Dienst, 1:380,160. Surveyor General, Jesselton, 1940. 1939-40. Map is partially made from aerial photographs. Detail is Compiled maps covering Talaud and Sangihe Islands and very sparse. Map is considered unreliable. Covers NE side of northern arm of Celebes. Topography by hachures and contours. British Borneo, from coast to about 50 miles inland. Considered fairly reliable. F. Geologic Map of Dent Peninsula, 1:200,000. Sarawak Oil- Portion of map covering part of northern arm of Celebes is fields, Ltd., 1936. Based on aerial photographs. Map is re- compiled map. Topography by hachures. Data shown is sparse. liable but shows planimetric data only. Considered unreliable. DECLASSIFIED By Authority of JCS letter, 7-25-75 By SR JUL 31 1975 Date Page I 2 MAP EVALUATION E. Atlas Midden Celebes, 1:100,000. E. C. Abendanon, 1916. sheets. These are not considered reliable. Sheets north of 40° Maps of limited coverage along routes of traverse. Topog- are reliable. raphy by contours. Some geologic data shown. Considered re- O. Celebes, 1:30,000. Topographische Inrichting, Topogra- liable. fische Dienst, 1923-34. F. Schetskaart van Midden Celebes, 1:200,000. A. C. Kruijt, Standard Dutch topographic sheets. Considered reliable. 1926. Covers southwestern arm of Celebes and Salajar. General compiled map of Middle Celebes. Topography by P. Celebes, 1:25,000. Topographische Inrichting, 1923-27. hachures. Not considered reliable. Standard Dutch topographic sheets covering area to south G. Meer-Gebeid van Midde Celebes, 1:30,000. Jaarbock and east of Makassar. Considered reliable. v.h. Mijnwezon in N.O.I., 1924. Q. Celebes, 1:125,000. AMS, 1942-43. Sparse data along route of traverse. Topography by contours. Compiled topographic map. Covers area south of 3°. Based Considered reliable. on Dutch 1:100,000 and 1:50,000 maps. First edition is not H. Schetskaart v.h. Cebergre, 1:200,000. Jaarbock v.h. Mijn- reliable. Second edition is considered reliable. wegan in N.O.I. 1920. R. Soola Elanden, 1:250,000. Topographische Inrichting, Compiled map. Topography by form lines. Considered fairly 1927. reliable. Covers all of the Sulu Group. Topography by shading. De- 1. Costarm van Celebes, 1:500,000. Jaarbock v.h. Mijnwezon tail sparse. Considered unreliable. in N.I., 1929. Compiled map. Detail is sparse. Topography by contours. Considered unreliable. Molukken Islands J. Costarm van Celebes on Pelang Eland, 1:100,000. Neder- A. Halmahera and vicinity, 1:100,000. Topografische Dienst, landsche Pacific Petroeum Mij., 1941. 1924-36. Standard reconnaissance topographic maps cover- Sparse planimetric and geologic data along lines of traverse. ing Halmahera, Ternate, Tidore, and adjacent islands. Considered fairly reliable. Topography by contours. Maps are considered to be only fair- K. Schetakaart v.h. Landschap Boston, 1:250,000. Topograph- ly reliable. ische Inrichting, 1916. B. Ceram, 1:100,000. Topografische Dienst, 1919. Compiled map. Topography by hachures. Considered unre- Topographic maps based on reconnaissance survey. Reliabil- liable. ity is fair except for positions which in the area of Pirve Basi L Geologische Kaart v.h. Eland Boston. 1:200,000. Topog. are out as much as 2' 30". rafische Dienst, 1936. Map covers Boston Island only. Planimetric and geologic de- Mindanao tail shown. Considered fairly reliable. M. Tokang Besi Eilanden, 1:250,000. Topographische In- No reliable surveys over Mindanao are available. Numerous richting, 1916. reconnaissance maps produced by the Philippine Department, Compiled map. Topography by hachures. Detail sparse. U. S. Army, between 1902 and 1913 are available but each Considered unreliable. covers only small local areas. Their reliability is poor. Jolo and Tawi-Tawi are covered at 1:80,000 and 1:62,500, respectively, N. Celebes, 1:100,000. Topographische Inrichting. Topog- rafische Dienst, 1919-37. produced by the Philippine Department. Their reliability is fair. At present AMS is producing 1:50,000 scale maps on the Covers southwestern arm of Celebes except for gap between Sulu Archipelago and 1:100,000 scale on Mindanao, which 4° and 4° 40's. Oldest sheets are in the south. Standard Dutch will incorporate the data from all available sources plus some sheets. Sheets south of 4° 40' do not check with later 1:50,000 corrections from aerial photographs. Chapter I Page I 3 BRIEF - M* 100° 100° III* us 120 189° 130° 139° 140° 148° 150 150° 140° SEA OF Tiegrain 15° Dairen d 39° JAPAN Tok KOREA YELLOW JAPAN SEA N° à C a H KYUSHU R T H Shanghai Z A N. Hangchow Yungkiaci EAST CHINA 29' SEA C F C à P A Cauton U . a A Bolligkong FORMOSA 20° Hangio - C E A N MY FRENCH Renggen € MARKAN MARIANAS INDO ISLANDS 19* IF THAILAND LUDON Bengkole Manifago PHILIPPINES Guen T CHINA 10° Salgon 10° % Bandon Palaman Negrah MALAY sTruk MINDANAO Palas PENNSILA Agrao C - I E " N. Pink - MALAY sorned STATES D 8 * Singapore SABAWAK Caletas Sine milmohare P N Schang, OF Padage 2839 o - a adminalty CRUMS Ceremi Behalf - - les NEW à 2 Natavia GUINEA New D.Area 8 Figres Dianden Urikal SOLOMON 8 ISLANDS LOCATION OF TWOR Dews Port Moresbri 10° CELEBES SEA AREA - - 5 Dargier Guil a 15" Deby Redial Scole from Davos Become o 500 1000 A U $ T R A L I A Townsville MILES 118° LM* 129° 130° 139° 140° 148° 150° 155° 10. Military Geography Approximate land area Island in square miles Comparable in size to The Celebes Sea lies northwest of Halmahera Island, and is enclosed by the Sangihe-Talaud Islands, Mindanao Island, the Halmahera Group 10,000 Vermont, Maryland, or Sulu Archipelago, Northeastern Borneo and Northern Celebes. Sicily Together with numerous small adjacent islands, these major Mindanao 36,906 Indiana, Maine, or Por- land segments, and the waters they enclose, comprise the Celebes tugal Sea Area. The maximum dimensions of the area are approxi- Northeastern Borneo 95,000 Wyoming, Great Brit- mately 1,100 miles east-west and 850 miles north-south. ain, or Korea The approximate size of each major island or island portion Northern Celebes 14,000 Switzerland, Nether- within the area is shown below: lands, or Salvador Page 1.4 - BRIEF ) 1 BALAWAN N. BORNEO MINDANAG NOTE: On the photographed model, vertical scale to horizontal scale is 5 to 1, BRIEF Page 1 . 5 MINDASAO P 1 North Page I 6 BRIEF There is a great deal of physical diversity within each island. objectives are located on comparatively narrow and discontinu- The area as a whole has unity, however, in that all the major ous plains. islands have: Because of the peninsular character of the larger island masses 1. Rugged interiors which are only partially explored and which included within the area, attention likely will be focussed also are bordered by small discontinuous plains. upon cross-island routes that will enable troops to cut off rela- 2. Interior basins or plains which are limited in size and in most tively large segments of the islands. These routes, with few ex- cases are difficult to reach. ceptions, lead through mountain passes, and undoubtedly would 3. Moist, warm climate the year round. 4. Heavy cover of tropical vegetation. cross numerous defensive positions. Very few routes are now 5. Adverse soil trafficability conditions during wet seasons. utilized by motor roads, and it is doubtful if many are suited for road construction. It is important to note, however, that in several places the The most significant smaller islands within the Celebes Sea local physical conditions are more favorable than indicated Area are those that have enough low flat land to be suitable for above for military operations, and make it feasible to utilize airfield development. Several such islands are located off the east these lands for bases in operations moving westward and north- ward toward Malaya, the northern Philippines, China, and coast of Halmahera, and in the southern portion of the Sulu Archipelago. Japan. B. Drainage and water supply. A. Relief (Figures I - 7 and I . 8, Plan 1). Poor drainage imposes major barriers to military operations A large portion of the area consists of rough, mountainous in many parts of the area, but water supply is adequate in most terrain, especially in the interior of the islands. Low flat lands are places and at most seasons. found mainly along the coasts, or on flood plains of the large rivers in Borneo and Mindanao. The coastal plains are usually (1) Rivers. narrow, and seldom are continuous for long distances. The rivers generally are short and rapid, without broad coastal Cross-country military operations will have to contend with plains. Their drainage basins are small. The main exception to difficult terrain problems throughout the area, with few excep- this rule is in Borneo, particularly in the eastern and north- tions. These exceptions are found in the Minahasa Region in eastern portions. In the interior of this island the broad area of the northeastern part of the northern peninsula of Celebes, and hilly to mountainous terrain, which receives heavy rainfall, gives in the central portion of Mindanao where there are wide stretch- rise to many large rivers. These rivers have built flood plains at the highland border, and flow in winding courses across these es of open, rolling terrain. Elsewhere, the interiors of the islands flood plains to the sea, The rivers are deep in their lower courses under consideration are mountainous, covered with dense for- and are practically the only easy routes of penetration into the ests, sparsely inhabited, and accessible only by forest trails. For interior of this large but little known island. From a military this reason most military operations probably will be directed point of view, however, they act more as barriers than routes, against peripheral objectives-primarily airfields, harbors, sup- since objectives are seldom located in the interior. These rivers ply points, and garrison bases along the coasts. Nearly all such are wide, deep, and susceptible to flooding, hence are effective BRIEF Page / 7 obstacles on overland routes from one coastal objective to an- D. Soil trafficability (Figure I - 9). other. Outside Borneo, there are only 2 rivers that would be sufficiently large to act as tactical barriers for large troop units. Soil trafficability refers to the capacity of soil to support the These are the Agusan and Mindanso-Pulangi Rivers on the movement of military vehicles. It applies especially to cross- island of Mindanao. country movement of vehicles and to traffic on unimproved roads made of local soil, rather than to traffic on improved or (2) Swamps. surfaced roads. Soil trafficability is determined by the type of soil Even more effective than the rivers as barriers to cross-coun- (textural grade, organic matter content and other profile fea- try movements are the swamps and marshes. Almost all of the tures), topography, vegetation, and weather factors. extensive ones are located on the flood plains of the large rivers The difference in trafficability between the coarse-, medium-, of Borneo and Mindanao. Small stretches of poorly drained land and fine-textured soils is not so great in the Celebes Sea Area as lie back of the beaches on many of the coastal plains and restrict in higher latitudes. This situation results from the type of rock coastal travel to narrow beach strips, thus limiting the area of weathering (lateritic) which is characteristic of the area and flat land available for airfields. which generally produces medium-, and fine-textured soils which are friable, and maintain their structure well, yet allow excess (3) Lakes. precipitation to drain rapidly. In spite of this ready drainage, the There are few lakes in the Celebes Sea Area, and most of general soil trafficability is moderately unfavorable. these are either small ponds in volcanic craters or shallow swamp The generally heavy rainfall is unfavorable to the movement lakes on river flood plains. The only lakes that appear to be of vehicles, and largely offsets the relatively favorable drainage suitable for floar plane use are Lakes Lanao and Mainit on Min- properties of the soils. Furthermore, the large islands have danao, Galela Lake on Halmahera, and Tondano Lake on heavily forested mountain regions in their interiors, which re- Celebes. strict movement to discontinuous coastal plains separated by rocky headlands and swampy areas. (4) Water supply. The regions exposed to the northeast monsoon generally have Most parts of the area have considerable rainfall. Numerous higher annual precipitation and a relatively wet season in the streams with headwaters in mountainous country afford fresh northern winter, whereas places exposed to the southwest mon- water at most places and at almost all seasons. On the very small soon tend to have most rain in the northern summer, but re- islands, however, particularly those of the low coral or sandy ceive less annual rainfall. Consequently, conditions for vehicular type, the only available fresh water is obtained either by collect- movements will generally be least favorable on the northeast ing rain water, or from shallow wells. coasts of the larger islands during the northern winter, and least favorable on the southwest coasts during the northern summer. C. Vegetation (Plan 2). Many of the smaller islands have steep, rocky slopes or, where they are of low elevation, have a heavy mangrove cover. The Wide expanses of unbroken rain forest are characteristic of most trafficable soils are those developed on coral atolls, coral nearly all the rough mountainous sections, and moss forest COV- islands, and uplifted ceral rock along the coasts of the larger ers large highland areas having exceptionally wet conditions. islands. These soils are generally trafficable at all times. Swamp forests are found on poorly drained lands, both upland No soil surveys of any extent have been made in the Celebes and lowland. On the coastal lowlands the type of vegetation is Sea Area. The soil trafficability map is based upon geologic and dependent in many cases, upon soil conditions, drainage, and the topographic information which itself is incomplete. The soil stage of cultural development of the area. Coastal mud flats in trafficability boundaries, therefore, are approximations. many cases have dense growths of mangrove. Where the land A very common soil-type consists of soils which range from is somewhat higher and less salty, but poorly drained, nipa coarse- to medium-texture and include sandy loams, stony loams, swamps are found. As a general rule, low sandy coastal plains and loams. In general, these soils should be trafficable except contain groves of coconut palms. Back from the sandy soil areas, during and immediately following heavy precipitation. How- the coastal lowlands are utilized for cultivated crops. The ever, where they occur in heavily forested mountain regions, amount of land so used, and the types of crops vary according to their trafficability will be very poor regardless of weather. locality. In Halmahera, Borneo, and on many of the smaller, Fine-textured soils also cover large areas, especially on low- sparsely populated islands, the vegetation on such plains is likely lands. These include silty clay loams, clay loams, and clays. to consist of scattered native gardens. Abandoned clearings These soils are slippery when wet, but they recover rapidly from grown up to tall coarse grass (kunei or cogon), or dense second- the effects of precipitation. Their trafficability probably is some- ary forest. what less favorable than that of the coarse- and medium-tex- In culturally more advanced portions of the area, such as tured soils. Fine-textured soils also occur in mountainous re- Celebes and Mindanao, open cultivated fields are much more gions where unfavorable topography restricts ground move- common. Rice and corn are usually important corps. Large plan- ment. tations are relatively rare outside Mindanao. Intermittently-flooded soils occur at many places along the Intermediate slopes, or low hilly land, commonly are in coasts of the islands, usually at the mouths of streams and rivers, either secondary forest or scattered clearings. Mindanao contains and in the interior river basins of the larger islands. These allu- the broadest areas of open grasslands. The Bukidnon and Lanao vial soils are frequently non-trafficable during and after rainy Uplands, in central Mindanao, have hundreds of square miles of periods. During dry weather their trafficability is moderately grasslands, and the flat interstream areas in these regions require favorable. Lowlands planted in rice are similarly flooded during little more than the cutting of the coarse tall grass to make them growing seasons, and are not completely dry even at harvest suitable for emergency airfields. time. Page I 8 BRIEF There are moderately large swamps and marshes on many (1) Routes to Kaoe Bay Region, Halmabera. parts of the coastal lowlands and along the larger river valleys. At the present time, there are no motor roads leading to the The swamps, or moeras, are very wet and muddy. Locally in such Kaoe Bay Region from other parts of the island. The only routes, areas a man may sink to his shoulders. The marshland, or dras- with the exception of the bridle track across the Dodinga land, also muddy but less deep, generally has no standing water. Ischmus, are along native footpaths. There are many of these, At many places mangrove swamps are serious obstacles to land- especially from the west coast, but few of them have potentiali- ing operations. The small scale of FIGURE I - 9 makes it unfeasi- ties for development into motor supply roads. ble to show the numerous mangrove swamps. (2) Routes to Bukidnon Uplands, Mindanao. E. Critical areas. This strategically important area in the central portion of There are 4 areas, each located on 1 of the major islands Mindanso has immediate approaches only from the north and of the region, that have critical strategic importance. These in- south, but there are several points along the periphery of the is- clude the Kaoe Bay Region of Halmahera, the Bukidnon Up- land from which good routes lead toward these 2 entrances. lands of Mindanao, the island of Tarakan off the east coast of The routes from the coastal points toward the Bukidnon Up- Borneo, and the Minahasa Region of Northern Celebes. Tarakan lands are already utilized by good motor roads, but they are Island is important because of its oil, which can be used as fuel more than just roads, since there is open, low terrain suitable oil directly, without being refined. The strategic importance of for deployment in most places. There are also a number of foot the other areas is the result of terrain and position. or pack trails through forested mountain country that lead toward the strategic area from both the east and west. (1) Kaoe Bay Region, Halmabera. This region is strategically located about midway between (3) Routes to and in Northeast Borneo. the southern portion of the Philippines and the Vogelkop or There is no approach to Tarakan Island other than by sea. westernmost part of New Guinea. Kaoe Bay is a large sheltered Furthermore, the mainland opposite the island consists of low, anchorage, and can accommodate an entire fleet. There are low, swampy, delta country, covered with mangroves and other flat plains in the vicinity, where the Japanese have several air- swamp vegetation. There is almost no access to the rest of North- fields in use or under construction. The rugged peninsulas on eastern Borneo except by boat along the coast, or up the rivers either side of the bay provide good defensive positions. to inland trail connections. (2) Bukidnon Uplands, Mindanao. (4) Routes in Northern Celebes. This region is located in the north central portion of the is- The Minahasa Region and the most critical points within it, land, and is the natural fortress of Mindanao. Its numerous air- the Lake Tondano area and the port of Manado, are accessible fields and potential airfield sites, its natural defenses, and its from the following points: along the macadamized road from road connections to both the northern and southern coastal areas, Lombagin to Amoerang; from either end of the Kanado-Kema make it the logical center of defense by ground and air forces. road; from either end of the Amoerang-Belang road; from (3) Tarakan, Borneo. Likoepang at the northeastern tip. Access to the interior is re- This island is located just off shore from the swampy delta stricted by steep slopes to the routes leading inland from the area at the mouth of the Sesajap River in Northeastern Borneo. points mentioned above, but once the plateau is reached, there It is important for its oil fields. It is not an easy area to attack, is a fairly good network of roads, and the terrain would permit as the island is bordered on nearly all sides by dense mangrove deployment off the roads in many places. swamps, and contains a hilly, heavily wooded central core. The Gorontalo-Loeandang route, a considerable distance west of the Minahasa Region, has some strategic significance because (4) Minabasa Region, Celebes. it bisects the northern peninsula. A possible potential route also There are 2 main objectives for military operations in this exists from Gorontalo, via the Bone Valley, eastward toward area. These are the harbor of Manado, and the airbases near the upper portion of the Ongkag Doemoga basin, from which a Tondano Lake. The Minahasa Region also has strategic im- portance because of the general suitability of the terrain for mili- motor road leads to Minahasa, via Lombagin. A military road tary operations, the relatively good network of roads, and the along this route was begun prior to the war, but was never com- available local labor supply. pleted. Much of it is through hilly to mountainous terrain. F. Routes to critical areas. G. Regional summary. The most important strategic routes are indicated on Plan 1 TABLE I 1 summarizes the data on relief drainage, vegeta- and on FIGURES I 7 and 10. tion, and water supply. TABLE I 1. MAJOR AREA TERRAIN REGION RELIEF DRAINAGE VEGETATION WATER SUPPLY Halmabera Southern Halmahera Narrow coastal plains; Small mountain Rain forest; narrow strips Wells and streams. hilly to mountainous in- streams,muchswamp of coconur plantations terior. on coastal plains. along the coast. BRIEF Page 9 TABLE I-1 (Continued) MAJOR AREA TERRAIN REGION RELIEF DRAINAGE VEGETATION WATER SUPPLY Central Halmahera Mountainous; few scat- Sangadji River; small Rain forest in the interior; Wells and streams. tered coastal plains; NE mountain streams; cultivation and second Peninsula, the most rug. narrow swamps. growth on coastal strips. ged. Northern Halmahera Open plains; rolling Kaoe River; other Much second growth; some Wells and streams. (Kaoe-Tobelo Low- country; dissected ter- streams small: grasslands in lower Kaoe lands and Ridges) races. swamps in middle valley; coconut planta- Kaoe valley and near tions along the coast. Akelamo. Northern Halmshera Low mountains; steep Lamo River and Rain forest. Streams. (Lamo-Kaoe Block) NW side. small mountain streams; swamps on N side of Dodinga Bay. Northern Halmahera High volcanic cones; Mountain streams; Rain forest in interior; Wells and streams. (Volcanic Range) rough hill country be- swamps at head of clearings and second tween; flat coastal plains Djailolo Bay. growth on coastal plains. on W. Northern Halmahera Undulating to flat plain; Tiabo River; swamps Scattered parches of grass- Wells and streams. (Galela Plain and narrow flat valley. N of Galela, and in land, gardens, coconur Tiabo Valley) middle portion of groves and secondary for- Tiabo valley; Gale- ests on plain; Tiabo val- la Lake. ley heavily forested. Northern Halmahera Narrow, steep mountain Small mountain Rain forest; small clearings Wells and streams. (N W Mountain range; narrow, discon- streams. along coast. Ridge) tinuous coastal plains. Morotai Island Rugged interior; widest Small mountain Rain forest; scattered Wells and streams. lowlands along SW coast. streams. clearings, gardens and sec- ond growth. Western Volcanic High volcanic cones; nar- No permanent Barren mountain tops; Wells and springs. Islands row coastal plains; fair- streams; small brush and forest farther ly gentle, undissected swamps on coastal down; gardens and planta- lower slopes. strips. tions on lower slopes. Barjan Islands Rough hilly terrain; low- Small streams, few Rain forest; small planta- Wells and springs. (Kasiroeta Island) land in S. have permanent tions and clearings along flow; swamps at W coast. end of S lowland. Batjan Islands Four mountainous penin- Small streams; Rain forest; plantations in Wells and springs. (Batjan Island) sulas, separated by low, swamps east of La- Laboeha area; scattered flat corridors. boeha and along clearings and second Sambaki Strait. growth. Barjan Islands Hilly interior; narrow No permanent Coconuts along coast, rain Wells and springs. (Obit Island) coastal flats on W and S. streams. forest in interior. Barjan Islands Hilly; narrow coastal No permanent Coconuts along coast; rain Wells and springs. (Mandioli Island) plain. streams; swampy on forest in interior. S coast. Mindanao Southern Mountains Mountainous; Koranadal Short mountain Rain forest; grasslands at Wells, cisterns, and corridor NW of Saran- streams. head of Sarangani Bay and streams. gani Bay. in Koronadal Valley. Central Mountains Mountainous; pass be- Swift mountain Rain forest, moss forest; Streams and springs. tween Digos and upper streams. lower slopes cultivated in Cotabato Basin. south. Davao Lowlands Flat to rolling. Small rivers; swamps Coconuts along the coast; Wells, cisterns, and at mouths of streams extensive abaca planta- streams. and at head of Davao rions; some forest. Gulf. a Page 10 BRIEF TABLE I - 1 (Continued) MAJOR AREA TERRAIN REGION RELIEF DRAINAGE VEGETATION WATER SUPPLY Eastern Mindanio Mountainous; isolated Mountain streams; Dense rain forest; scattered Wells and streams. coastal plains at heads of no large rivers; some clearings on coastal plains. bays; rough, hilly penin- swampy areas on sulas. coastal plains. Agusan Basin Broad, flat lowland. Agusan River sys- Mostly dense rain forest; Wells, cisterns, and rem; extensive marsh- scarrered clearings along streams. es and swamps. the lower courses of the river. Bukidnon Uplands Broad, sweeping slopes, Rapid streams; not Mountain areas in rain for- Wells, cisterns, and deeply entrenched in the navigable; those in est or moss forest; wide springs. N; included volcanic north in canyon-like areas of grassland; patchy mountain areas; many valleys. forest in extreme S. level upland areas. Lanao Uplands Diverse terrain; moun- No large rivers, but Much open grassland; scat- Wells, cisterns, and rains, plateaus, coastal some may be obsta- tered cultivation N of streams. plains, and rolling coun- cles after heavy Lake Lanso; dense forest E try; latter dominant. rains; swamps at of lake. head of Iligan Bay. Western Mindanao Mostly mountainous; Sibuguey River: Rain forest; scattered grass Wells, cisterns, and some hilly country; wid- small, mountain lands on Zamboanga Pen- streams. est plains on extreme N streams; much insula; coastal plains on N and S. swamp on coastal and S cultivated. plains at mouths of streams. Cotabato Basin Flat basin bordered on N Mindanao River sys- Rice cultivation in lower Wells, cisterns, and by low terraces, steep tem; extensive valley; marsh grasses, open streams. edge on SW; some iso- marshy areas in cen- grassland, and secondary lated flat-topped hills. tral portion. forest in rest of basin. Sulu Basilan Island Hilly to mountainous in- Small streams; Rain forest; N plain culti- Wells, cisterns or Archipelago terior; widest lowland on swamps along many vated; some plantations springs. N. coastal stretches. along the coast. Jolo Island Volcanic hills and "peaks Few streams; swamps Mostly under cultivation or Wells, springs or cis- separated by wide sweep- along low sheltered second growth; forests on terns. ing slopes; most rugged coasts. peaks. on W. Tawirawi Island Rough, hilly interior; a No permanent Mostly rain forest; grass few coastal flars. Inadequate supply. streams; a few coast- and clearings at SW end. Shallow wells and cis- al swamps. terns. Borneo British North Mountainous interior es- Short mountain Rain forest; some grassy Borneo pecially toward W; nar- Wells, springs, and streams on W coast, clearings, second growth, streams. row coastal plains on W except Padas R.; and cultivation along W interrupted by hills; large rivers flow to E coast; swamp forests along broad river flood plains coast; extensive E coast, some moss forest. on E coast. swamps SE of San- dakan, and at river mouths. Durch East Borneo Rough hill land; some Large river systems: Rain forest; scattered cul- interior basins; broad Sembakoeng, Sesajap, Wells, springs, and tivation and secondary for- streams. river flood plains; isolat- Kajan, Beraoe, and est along streams. ed ridges and hills; moun- Mahakam. rains on W border. Celebes Minahasa-Bolaäng- High volcanic cones; Mountain streams; Forested summits; much Mongondow plateaus; narrow coastal Lake Tondano. Wells, springs, and cleared and cultivated land streams. plains; several passes. (rice, corn), and secondary growth. Northern Peninsula Central mountain range; Mountain streams. Mountains covered with narrow coastal plains; Wells, springs, and rain forest; lower slopes only one gap in range streams. scattered second growth (Gorontalo-Koeandang). and clearings; coastal plain cultivated land, second growth, and swamp forest. BRIEF Page / 11 11. Oceanography 12. Coasts and Landing Beaches A. Tides. A. Halmahera sector. The tides in this area are complex, varying from semidiurnal (1) Coasts. tides with some inequality between morning and afternoon tides (a) Djailolo Bay and vicinity. Djailolo village can be ap- to those that become entirely diurnal (1 tide a day) for cer- proached either directly through Djailolo Bay or overland from tain portions of each month. At some places, the average range Sahoe Bay. Sahoe Bay approach is clear to the 18-foot curve at the time of tropic tides exceeds 9 feet. which lies about 1,000 feet off the beach. From the shore, a broad plain extends inland around a 3,705-foot mountain to B. General circulation. Djailolo, on the north shore of Djailolo Bay. Direct approach through Djailolo Bay is by way of a narrow channel in the fring- The greatest flow of water into the Celebes Sea is southwest- ing drying reef, which extends more than 300 yards from the erly through the passage between the southeast coast of Minda- low shores of the bay. There are several shoals off the coastal reef. nao and the Talaud Islands. Within the Celebes Sea, the water Extensive mangrove swamps are intersected by small sandy circulates in a counterclockwise direction, and most of it leaves beaches, which are usually soft but have good exits. There are the area through the northeastern part of Molucca Passage. Some few good landing sites, the best being at Djailolo wharf. water also enters from the Sulu Sea through Sibutu Passage ex- cept during the spring and summer when the current is reversed. (b) Dodinga Bay and vicinity. Dodinga is located at the Similarly, some water leaves the area through Makassar Strait. head of Dodinga Bay on the narrow isthmus that separates Do- Strong tidal currents are to be expected in numerous locali- dinga and Kaoe Bays. In Dodinga Bay the 10-fathom curve is close to shore, but there are reefs on both north and south sides ties within the area. of the bay. Southward of the bay the coast is free of dangers and C. Sea and swell. can be approached to within 1/2 mile. There is good anchorage off Dodinga village. Dodinga can also be approached by trail or High sea and swell are infrequent in the areas covered by cart track, about 2 to 3 miles long, across the isthmus from this report. The 4 areas differ slightly in the monthly distribu- Kaoe Bay. tion of the amounts of sea but, in general, the sea is least dis- (c) Hiri and Ternate Islands. The shore of Ternate Roads turbed during April, May, and June and is roughest during De- is bordered by a coastal reef that narrows southward. The 3. cember and January. Sea and swell are predominantly from the fathom curve lies about 100 yards and the 10-fathom curve northeast from November through April and from the south or about 200 yards beyond the reef. A semidiurnal tide predomi- southwest during the rest of the year. nates, and a strong current sets through the roads at times. The coasts of Hiri and Ternate Islands are steep-to in places, with al- D. Sea-water characteristics. ternating beaches. There are narrow coastal reefs but almost Water temperature at the surface ranges between extremes of none that dry. Approach is clear to the reefs. Landings at high 76° and 88° F., and at 300 feet between 60° and 84° F. Tem- tide by shallow-draft landing craft should be possible in the perature gradients are not common just below the surface, but lee of Ternate Island in all seasons. there is an average difference of 9.4° F., with a maximum of (d) Galela Bay. The bottom falls off sharply, with depths 28° F., between the surface and 300 feet. of 20 fathoms within 300 yards of the shore. The harbor is not Extreme salinity values of 30.91 and 36.20 parts per thousand safe during the northwest monsoon. Currents are negligible, have been recorded at the surface; the average surface salinity with a semidiurnal tide predominating. The western shore is is 34.03 parts per thousand. Lower values are to be expected backed by a broad plain through which flows the Tiabo River. close to shore owing to fresh-water runoff. At a depth of 300 An impenetrable marsh at this point cuts the area in two, There feet, the salinity ranges from 33.20 to 37.74 parts per thousand, is a beach in the northern section and another at Galela itself. with an average of 34.62 parts per thousand. Landing is possible, even with the heaviest surf, south of the islet Density layers are frequently found below 100 feet. Only rare- west of Bongo Point. The coast may be approached close to. ly will submarines be able to balance on these layers, and ballast (e) Tobelo-Miti. A clear channel runs between the foul changes of 2,000 to 19,000 pounds will be required., ground that fronts the Halmahera shore and the Tobelo Islands. Echo-ranging conditions are usually fair throughout the year, There is little current berween the islands and the shore. The except when the background noise level is high. Assured echo coast of Halmahera in this area is mostly low. South of Tobelo ranges of 1,500 to 2,000 yards may be expected away from the the shore is swampy, with mangroves. The Tobelo Islands are islands. Screw noises have been recorded at a maximum distance low, of coral, well-wooded. Most have fringing reefs. There are of 10,000 yards and pinging at a distance of 12,000 yards. numerous beaches on the mainland and the islands, most of Away from land the water is probably relatively clear and them fringed by wide reefs. The best anchorages are at Tobelo blue. and Miti. All shoals in this area discolor well. (f) Kaoe Bay. Entrance to Kaoe Bay is deep in the fair- E. Bottom sediments. way but has a 51/2-fathom patch on its western side and a 3½ The shelves surrounding the islands in the Celebes area are fathom bank on the east. The northwestern shore of Kaoe Bay narrow. For the most part, the shallow-water bottoms consist is in general rather low, with sandy beaches and mangroves of alternating patches of sand and coral and some stone. In large around the mouths of the rivers. The southeastern shore is fair- bays and off the mouths of the rivers of Mindanao and Borneo, ly high and steep with some exceptions. At Kaoe Roads, in the the bottom is generally mud. Mud may also be expected in the northern part of Kaoe Bay, a semidiurnal tide predominates; the more protected bays on the smaller islands. 10-fathom curve lies about 20 miles from shore. Westward of Page I 12 BRIEF Kaoe is a large bank extending 125 miles offshore. There are the island, having steep-to coasts in general, except on the beaches at intervals along this part of the coast. southern side where a bank of soundings joins it to Salebaboe (g) Wasile Bay. The main channel leading into Kaoe Island. Near the bights on the west coast the hills draw away Bay and Wasile Bay is close east of Boebale Island. Depths in from the shore. Broad reefs are found there. The north coast Wasile Bay range from 7 fathoms near the shore to 34 at the is rocky and steep; the east coast is fronted by a drying coastal entrance. The south coast of the bay is rocky. There is a wide reef with large rocks in places, while that on the south is fringed mud bank on the east coast. Northward, the shore is sandy and by a reef nearly 1 mile in width. narrower. Wasile Bay is clear. There are several good anchorages off this island, as well as (b) Morotai Island. The west coast, between Point De- several landing places on the coast. Dangers to navigation are hegila and Wajaboela, is fronted by numerous shoals, reefs, and prevalent near Mawawo, Kiama village and in Liroeng Strait. Salebaboe Island, southwest of Karakelong is about 15 miles islets. Southeastward of Wajaboela Point, where there is a low plain, is a bight forming a harbor protected by 3 drying coral long, having a saddle-like formation of densely wooded hills at the middle of the island. There are some sand beaches here and reefs. The bight is fringed by a narrow drying reef and is fronted by numerous shoals and reefs. Northward of Wajaboela the there, varied by large, rocky lumps of coral. The island is sur- coast is steep-to. Landings during the north monsoon are re- rounded by a very narrow shore reef. The west coast is rocky ported practically impossible except at Berri Berri, Boesoeboe- and steep; the east coast is low and swampy near Moronge vil- soe, and Sangowo. lage. There are several probable landing beaches on the island, but anchorages are limited. (2) Landing beaches. Kaboeroeang Island, the southernmost of the group, is 8½ Scattered beaches, usually associated with a fringing coral miles in length. lts 2 summits are 1,328 and 1,578 feet in reef, occur along all the coasts of Halmahera. The most exten- height. The coast is rocky, broken by sandy beaches, and fringed sive beaches lie on the west coast between Loloda Bay and Do- by a narrow, steep-to coastal reef. Probable landing beaches can dinga Bay and on the east coast in Galela Bay, Boeli Bay, and be found in several places, but safe anchorages are not, in gen- Weda Bay. The beaches are backed generally by a narrow coast- eral, available off this island. al plain leading inland to steep slopes. Numerous small off- (2) Landing beaches. lying islands obstruct the approach to sections of the coast. Roads or trails affording exit from the beaches are most numer- Small beaches occur on all the Sangibe Islands, usually at ous on the northern peninsula. Beaches on Morotai occur on the small villages and generally along the inner edge of a fringing east, south, and southwest coasts. The northwest coast is steep coral reef. The most extensive beach lies along the west shore and has no beaches. of Sangihe Island itself, extending westward from Tahoena Bay. The approach to the beaches is obstructed locally by small off-lying islands. Generally the terrain inland rises in steep B. Sangihe-Talaud sector. slopes, except along the east coast of Sangihe Island where (1) Coasts. there are numerous river valleys. Trails and in a few cases sec- Between Mindanao and the northeastern point of Celebes ondary roads generally follow the coast at least part way around lie the Sangihe and Talaud Islands. The Sangihe Islands are vol- most islands. canic and rise from very deep water. The Talauds are hilly, but There is little detailed information on landing beaches on the in general, are lower. Talaud Islands, but those best known occur in Beo Bay and Of the Sangihe group, Sangihe Island is the largest, being 26 Poeloetan on Karakelong Island; at Liroeng on Salebaboe Is- miles in extreme length and rising to a height of 6,102 feet. The land; and at Mengarang on Kabaroeang Island. Other probable coast has several bays, and is steep and rocky in places, low in beaches occur in small bays between rocky headlands and along others. the open southern coast of Karakelong Island. The beaches are There are several landing places as well as probable landing often associated with a fringing coral reef. The offshore ap- places on Sangihe. Good anchorages may be found all around proach is generally clear. The beaches are generally backed by the island. a narrow coastal plain, often with narrow river valleys lying be- Other important but smaller islands in the Sangihe group tween fairly steep wooded hills. A trail or road generally paral- are: from north to south-Toade Islands, Kalama Island, Kaha- lels the coast, but with few known connections inland. kitang Island, Mahengetang Island, and Para Island. Siaoe Island is the southernmost large island of the Sangihe C. Mindanao sector. Islands. It has good beaches on the east, west, and south coasts, (1) Coasts. near the most important settlements. These are connected by a coastal road and by cross-island roads and trails. In the Surigao area the coast between Claver Point and Bilaa Point consists principally of a narrow, wooded plain fringed by South of Siaoe are the islands of Tahoelandang, Roeang. and mangrove swamps and backed by timbered mountains. A num- Biaro. The first 2 are high, steep-sided volcanoes. The last is ber of mangrove-covered islands occur immediately off the mid- lower but also hilly. dle of the coast. Between Bilaa Point and Mount Tubay forested The 3 main islands of the Talaud group are Karakelong, Sale- mountains rise almost from the water's edge. Anchorage is avail- baboe and Kaboeroeang. They are hilly and heavily wooded for able off Surigao and Placer. A number of detached dangers occur the most part, but in many places on the coast, they are low and off the east coast, but none are present from Bilaa Point south- swampy. ward. Karakelong Island, the largest and northernmost island of In the Cagayan area the eastern and western shores of Maca- the group rises to a summit of 2,231 feet near the middle of jalar Bay are mountainous, but the head of the bay is bordered BRIEF Page I 13 by a narrow coastal plain. A number of anchorages and several (2) Landing beaches. off-lying dangers occur in the bay. In general the most extensive beaches along Basilan and Jolo In the Misamis area the entire shore line of Iligan Bay con- Islands occur along the northern coasts. They are associated with sists of a narrow coastal plain backed by wooded mountains. The a fringing coral reef, usually with an otherwise clear approach, best anchorages are in Port Misamis, which contains numerous and in general are subject to heavy surf during the season of the detached dangers. northeast monsoon. Along the southern coasts, the beaches are In the Zamboanga area rugged mountains rise directly from generally located along the inner edge of a fringing coral reef at the western coast of the peninsula. There is good anchorage at small villages. They are separated by extensive stretches of man- Port Santa Maria and there are few off-lying dangers. A narrow, grove-lined shore, and in some places have poorer means of exit wooded coastal plain borders the southern and eastern shores of to the interior than do those along the northern shores. the peninsula. Anchorage is available east of Zamboanga, and numerous dangers face the eastern coast. E. Northeast Borneo. In the Davao Gulf area an extensive, swampy coastal plain lies at the head of the gulf, but the western and eastern shores (1) Coasts. are predominantly mountainous. The large wooded island of (a) Jesselton area. Jesselton Harbor, at the south end of Samal is opposite Davao. There is good anchorage at Malalag Gaya Bay on the west coast of Borneo, is a fairly safe anchorage. Bay and Davao, and at a few points along the east shore of the It is bounded on the west by Gaya Island and on the east by the gulf. The head of the gulf and the southern part of its western mainland. The coastline at Jesselton consists of long, narrow, shore are practically free of dangers, but detached reefs and sandy beaches separated by rocky bluffed headlands, which rise shoals face most of the remaining shore line. steeply from the sea to altitudes from 150 to 1,000 feet. Behind the beaches there are irregular discontinuous and locally (2) Landing beaches. swampy plains which border the coast and extend inland along Beaches are numerous along the coast of Mindanao, both on the major rivers. open coasts and in bays, near all important centers. The most (b) Marudu Bay area. Kudat Harbor is situated on the extensive beach areas lie along the northwestern shores of western shore of Marudu Bay between Point Bornugus on the Davao Gulf. Most beaches are associated with fringing coral north and Cape Tigasamil on the south. From Aru Point to reefs. The offshore approach is generally clear, except along the Melau Island the entire coast is fronted by a shelving reef 200 northeastern coast and parts of the southern coast, where small to 1,400 yards wide. The 5-fathom curve passes just off the off-lying islands occur. Beaches exposed to the northeast and outer edge of the reef. In the vicinity of Kudat Harbor, hills 200 southwest are subject to the heaviest waves and surf during the to 400 feet high rise steeply from the water or from narrow seasons of onshore winds. A narrow coastal plain backs most of sandy beaches, except for a low marshy plain extending about 3 the beaches, and it is commonly succeeded inland by steep wood- miles north and northwest of the town. The harbor offers good ed slopes. A road or trail is accessible from most of the beaches. anchorage in 6 to 9 fathoms over a mud bottom. There are a few dangers off this part of Marudu Bay, the most prominent D. Sulu Archipelago and Basilan Island. being Sandilands Rock at the harbor entrance. (c) Sandakan Harbor area. Sandakan is located on the (1) Coasts. northeastern coast of British North Borneo southeast of Labuk Basilan Island lies adjacent to and southwest of the Zambo- Bay. The harbor affords one of the best anchorages in North anga Peninsula of Mindanao. There are several routes of rela- Borneo. The water off the harbor entrance is free of dangers tively clear approach to this large island, and there are good and is fairly deep, but to the northwest and southeast there are landing places and beaches near the important coastal settle- shallow depths containing several small rocky islands and reefs. ments and cross-island trails. Much of Basilan Island is moun- Sandakan Peninsula between Labuk Bay and Sandakan Harbor tainous and heavily wooded. is a low plain with a few rolling hills. The northern part of Jolo Island, near the center of the Sulu Archipelago, is 43 Sandakan Harbor is formed by steep hills. Coalescing deltas of miles long east and west, and 3 to 13 miles broad from north many streams draining the interior form the western and south- to south. It is composed of several groups of volcanic peaks, ern parts of the harbor. Near the stream mouths, the deltas are which have long slopes and wide, intervening valleys. The high- fringed with sandy beaches, elsewhere are soft mud flats. The est peak is from the west end of the island to 2,665 feet above entrance to Sandakan Harbor is bordered by extensive mud the sea. In general, the hills have little timber. The lower slopes flats which have a maximum depth of 3 fathoms at high water. and the lowlands are intensively cultivated. The coasts are well (d) Darvel Bay. The northwestern shore of Darvel Bay wooded, clear and steep-to, for the most part, as are also the islets is indented for about 5 miles by Lahad Datu Harbor. There is and islands bordering them. The several bays formed by coastal generally deep water off the coast between Bagahak Point, to the east of the harbor, and Skertchley Point on the west, except indentation provide good anchorage, especially so at Jolo, the off Darvel Peninsula where a 3-fathom shoal is located. The capital, which is situated on the northwestern coast, in a bight coastline westward of Bagahak Point is generally lacking in ex- about ½ mile eastward from Belan Point. Other good anchor- tensive coastal lowlands although isolated mangrove swamps ages are at Dalrymple Harbor, Tandu' Batu, Maimbung Bay, appear at the mouths of streams. The hill and mountain slopes Tutu Bay, Capual Channel, and Patotol Bay. commonly descend to the beach. Low cliffs are reported between Dangers to navigation are numerous in Capual Channel Kennedy Bay and the Sebahat River. From Kennedy Bay to La- north of Liangliang, off Bulicutin Island, Panganaa Island, in had Datu there are low mangrove swamps. To the west, near Si- Maimbung Bay, and off the coasts of Jolo. lam, steep slopes border the coast. From Silam to Skertchley Page I 14 BRIEF Point the coast is lined with mangrove swamps. The best an- In the Kema Bay area the waters are shallow for some dis- chorage is Lahad Datu Harbor, although there are others at tance offshore. Except in the bay proper the coast is fringed by Silam, Kennedy Bay, southwest of Silam, and Lamak Bay. There a broad coral reef. A narrow coastal plain, mantled by coconut are few dangers to navigation off the coast near Lahad Datu palms with occasional patches of woods and grassland, separates except along the western end of Darvel Bay, where there are steep, timbered, volcanic slopes from the sea. A few short beach- numerous reefs and shoals. es border the shoreline. Anchorage may be found off Kema. De- (e) Sibuco Bay-Tawau area. Offshore depths, both with- tached shoals and rocks occur near the entrance points. in and outside Cowie Bay, are everywhere regular, 7 to 16 fath- In the Manado Bay segment, rolling, wooded foothills, flank- oms prevailing, with few dangers to navigation. The 5-fathom ed by a very narrow coconut-covered coastal flat, rise from curve lies less than a mile offshore on the north; on the south, waters which deepen very rapidly offshore. The broad valley of the Manado River leads southward from the head of the bay. the edge of the shallow water is for the most part steep-to, and depths of over 6 fathoms prevail close inshore. From Mount The entire shoreline is bordered by a dark sand beach. Anchor- Putri on the north, the coast trends in a general northwest direc- age exists off the village of Manado and off-lying dangers are tion and is intersected by numerous small creeks and rivers. The absent with the exception of 2 submerged rocks a short dis- ground is flat or generally undulating with locally small steep- tance south of the harbor. sided hills rising 200 to 500 feet above the plain, which is inter- In the Amoerang Bay segment, the deep waters of the bay are rupted by lines of rocky hills, on either side of Tawau. The encircled by a narrow, coconut-mantled coastal plain which is south side of Cowie Bay is formed by Sebatik Island, about 20 separated from the rugged interior mountains by low benches. miles long and 7 miles in average width. A range of high dense- At several localities sandy beaches or mangrove swamps border ly wooded hills traverses the island throughout its length. There the shoreline. Anchorage exists off the town of Amoerang, and is good anchorage within Cowie Bay. a few scattered shoals very near the shore form the only dan- (f) Tarakan Island area. Depths are irregular off the gers. In the Koeandang Bay segment the relatively shoal waters of Sesajap Delta and for the most part are very shallow to a dis- tance of 15 miles offshore, except in the passages north and the bay are studded with numerous islands and detached dan- south of Tarakan Island, where depths up to 20 fathoms are gers. The coast consists of small coconut-covered flats backed by benches and wooded foothills, and separated by forested spurs found. The coast berween Ahoes Island on the north, an unnamed point abreast the mouth of Salinbatoe River on the south, is in- extending seaward from the foothill belt. Much of the shore- tersected by many rivers of which Sesajap River is by far the line is fringed with mangrove and nipa swamps. The waters largest. The delta of the Sesajap River, contains a large number east of Pajoenga Island afford anchorage. of small islands, berween which 3 main passages give access from In the Tolitoli Bay segment the broad, beach-fringed, culti- the sea; these are subdivided by many of lesser importance. The vated plain encompassing the bay is fronted by a wide submarine coast here is low and flat, the only recognizable points from shelf under moderate depths, on which lie several islands and numerous reefs. A semicircle of forested mountains behind the seaward being the islands of Menoeloen, Tarakan, Bunju, and the Senbakung Hill. There is good anchorage in Tarakan Harbor. coastal flat terminates in blunt rocky promontories. The coasts Three reefs about 15 miles off the coast of Tarakan Island are northward and southward from the bay itself consist of moun- dangers to navigation. tainous headlands separated by small flats. Anchorage is avail- able off the village of Kampoengbaroe or Tolitoli. (2) Landing beaches. (2) Landing beaches. On the northwest coast of Borneo, from Brunei to the north- ern tip of the island, there are a number of extensive, wide, sand Many beaches are found on both the north and south shores beaches. Coral reefs are generally lacking, and approaches are of the northern arm of the Celebes; for the most part they are clear. During part or all of the year, surf may be the critical fac- small and separated by numerous mountain spurs which run tor in landing. Some of the beaches are backed by swampy down to the shore from the interior highlands. The longest and ground, but most of them have good exits to a trail, road, or widest beaches line the broad bays on the northwestern shores; railroad. On the north, northeast, and east coasts, as far south these are in many places backed by narrow dune areas. The as the Equator, there is an almost complete lack of landing south shore is generally rockier and the beaches smaller than on the north shore. Areas of coral reef are scattered and discontinu- beaches except in the sections described in detail. Even in these sections the beaches are in general less favorable than those on ous, and front about half the beach areas. Mangrove swamps the northwest coast. Elsewhere, the shore is mostly low, covered in many places lie inland of the reef, with mangrove trees grow. with mangrove and fringed by coral reef, and backed by swampy ing out on the reef itself, particularly on the north shore. In ground without exits. general, exit from the beaches is provided by trails paralleling the shore either on the beach or a short distance inland from it. F. Northern Celebes sector. (1) Coasts. 13. eather and Climate In the Gorontalo Bay area rugged, forested mountains rise steeply from deep water, except at the head of the bay, where The Celebes Sea Area has a humid tropical climate character- the mountains are broken by the narrow estuary of the Bolango- ized by gentle winds, monotonous heat, extremely high humid- Bone Rivers. Locally, short strips of sandy beach, backed by coco- ity, heavy cloudiness, and frequent intense rain showers. nut groves, fringe the shore. Anchorage is available along the Due to monsoon influence, wind direction is northeast from eastern shore at the head of the bay, and no detached dangers December through March and southwest from July through exist. September. From April through June and from October through BRIEF Page I 15 November the intertropic front lies within the Celebes Sea re- the intertropic front lies over the area: April through June, and gion and northeast monsoon and southwest monsoon each domi- October through November. nates part of the area. The airmasses of both the monsoons have had a long journey D. Chemical warfare. over warm tropical seas and are warm and moist by the time they arrive over the Celebes Sea Area. Thus, despite the com- Chemical warfare would be greatly restricted by frequent tur- plete reversal of wind flow from season to season, in most re- bulence and unstable air. Constant heat, high humidity, and spects the climate is monotonously uniform throughout the year. frequent heavy rains would affect the rate of evaporation and With most weather elements, diurnal variation, associated hydrolysis of many chemical agents. with daily heating and cooling of the earth, is of greater mag- nitude than the seasonal variation. Differences in latitude, in altitude, and in exposure to wind 14. Towns and Port Facilities and sea cause climatic contrasts among different parts of the region. High mountains rise into a cool zone of persistent cloud- The Celebes Sea region contains no large cities and relatively banks, but only the highest peaks have snow. Even minor topo- few towns, of which not more than half a dozen have more than graphic differences cause large place-to-place contrasts in most 10,000 inhabitants. The population of the largest town, Mana- weather elements: local differences of exposure or slope com- do, in Northern Celebes, was less than 30,000 in 1930. Nearly monly give nearby places dissimilar wind and rainfall regimes. all the towns are located along the coasts, and the principal towns were the principal ports as well. Often, long stretches of A. Ground operations. shoreline have no settlements except small native villages, and the interior regions are still more sparsely populated. The num- Ground operations would be seriously restricted by exten- ber of white inhabitants is everywhere very small, even in com- sive and persistent muddy soil conditions and occasional floods. mercial and administrative centers, while the Chinese are com- Throughout the area, heavy rains are possible in any season. paratively numerous and play an important part in the economic However, winter rainfall is generally heaviest at places exposed and civic life of all the larger settlements. Native villages to the north and east, summer rainfall heaviest at places exposed throughout the area vary greatly in size and form, but almost all to the south and west. Constant high temperatures and moist are self-sufficient units. air are accompanied by difficult health problems as well as con- The Mindanao sector was by far the most developed and had stant trouble with rust and mold. the greatest concentration of both principal and secondary ports, with facilities greatly in excess of those found elsewhere. Zam- B. Air operations. boanga had a daily cargo clearance capacity of 2,420 short tons, Low-level air operations would encounter few weather re- while its nearest rival in other sectors, Sandakan on Borneo, had strictions. Turbulence is common, but is usually sufficiently lo- an estimated capacity of 450 short tons. calized to be avoided. Very low ceilings are rare. Visibility is For location of ports in the area, see FIGURE I 11. generally good. Heavy cloudiness at medium heights would interfere frequently with high-level operations. Icing occurs A. Halmahera sector. only at high levels. Most of the settlements on Halmahera and the neighboring Effective incendiary bombing would be greatly restricted by islands are primitive native villages on the coast. The areas of the prevailing dampness and low wind speeds. heaviest settlement are the islands of Ternate and Tidore and Parachute operations would occasionally be hampered by sur- the adjacent areas of Halmahera. face winds. However, low wind speeds predominate in all sea- sons. (1) Ternate. The largest town and principal port in the Halmahera area, C. Naval and amphibious operations. Ternate, is on the eastern coast of Ternate Island, across Do- dinga Bay from Halmahera. It is accessible by land, sea, and Naval and amphibious operations would encounter relatively air. little interference by wind; strong winds and gales are infre- quent. Prevailing low wind velocities are reflected in low fre- (a) General facilities. Among facilities that were located quency of heavy sea and swell. Disturbed sea conditions are pos- at Ternate were: a 120-volt, DC lighting system powered by a sible in any season during a thundersquall, but the prevailing diesel prime mover; a water system capable of supplying drink- wind velocities are too gentle to cause heavy sea. ing water to ships at the wharf; a radio station; cable connec- tions with Manado; and a 55-bed civilian hospital and a 13-bed Direction of sea and swell corresponds to direction of prevail- military hospital. Wells provided an adequate supply of drink- ing wind. On shores exposed to the north and east, sea and surf ing water for the town. Billeting facilities might be available conditions are least favorable from November through April in military buildings, hospitals, churches, schools, a prison, a when winds are northeast. On shores exposed toward the south hotel, a sultan's palace, houses, and other town buildings. and west, sea and swell is onshore from June through Septem- (b) Port facilities. Anchorage is unlimited in the open ber. Disturbed sea is most frequent when the prevailing winds Ternate Roads, with depths of 15 fathoms about 1/4 mile off- are onshore and are intensified by the afternoon sea breeze. shore and about 30 fathoms, 800 yards offshore. The roadstead There is little prospect of effective concealment of fleet move- is fairly well-protected, but holding ground is bad, the bank ments or landings by fog or low cloud. Most suitable conditions steep and the tidal stream strong. Troublesome rollers occur for concealment would probably be found during times when from December to April and a heavy swell frequently in De- Page I 16 BRIEF cember. The southwestern approach through Gamme Lamo reported for these villages. Storage facilities were limited to Channel has a least depth of 19 fathoms and the approaches small warehouses, usually for copra, at some of the villages. from northward and southward are deep and generally clear. The only commercial pier, Hertog Hendrik Pier, was of tim- B. Sangihe-Talaud sector. ber on metal screw piles, T-head, 198 feet on the face and 430 There are no major towns nor ports in the sector. Serrlements feet long, with an approach about 18 feet wide. Depth of water consist of a few small locally important centers and a large num- at pier face was 13 feet. There were no mechanical cargo-han- ber of native villages. Much of the area's administration and dling facilities. Two narrow-gauge tracks connected the pier head trade was handled from Manado, Celebes. There are 9 coastal with a coal storage shed about 700 feet inland. A fresh water villages of local importance, all of which had some minor port pipeline, laid onto the pier, could deliver 40 tons per day, facilities or were ports-of-call for vessels of the K.P.M. The chief pumped from the town wells. town was Tahoena, an administrative and trading center on There were 3 other small boat piers: the Japanese fishing Sangihe Island. Hoeloe was the chief center on Siace Island, boar pier, 40 feet wide at the face and 95 feet long; the Resi- Tahoelandang, on the island of the same name, and Beo was dency Pier for small boat landings, 10 feet wide, 250 feet long the chief center of the Talaud Islands. and with 2 feet of water at the head; the Sultan's Pier for small There were radio stations communicating with Manado at boar landings, timber open-pile, 40 feet wide on face, 855 feet Tahoena and Beo, and Tahoena had a 10-bed hospital. long, and with only a few feet of water alongside. Anchorage for large vessels is in open roadstead, except at Storage facilities consisted of: a stone and tile cargo shed, 225 feet by 40 feet; a stone and shingle cargo shed, 100 feet by 60 Dagho and Behongang, where there is sheltered, deep-water feet; a wood and corrugated iron storage shed, 120 feet by 80 anchorage of limited area. Some villages have sheltered anchor- feet; a coal storage shed with adjacent open storage yard; an age for shallow-draft vessels close in. open storage yard for oil in drums. Most of these were destroyed Villages which had piers for small boats, generally with or damaged by the Dutch but the Japanese have since built a depths between 3 and 6½ feet at the pierhead were: Beo, Ta- number of structures, believed to be warehouses, in the area ad- laud Island, 426-foot stone pier; Tahoena, Sangihe Island; jacent to and southward of the Hertog Hendrik Pier. Dagho, Sangihe Island, 600-foot stone pier; Behongang, Kaha- About 20 motorboats were based at Ternate. kitang Island; Hoeloe, Siaoe Island, wharf; and Tahoelandang, The only repair facility was a small machine shop for the Tahoelandang Island. Japanese fishing boats. No cargo-handling machinery has been reported. There is no The unloading capacity is estimated to have been 160 short information as to storage facilities but it is probable that the tons.* K.P.M., which called at all of these villages, had warehouses at some of them. No repair facilities have been reported although (2) Villages. the natives of Tahoelandang are said to be noted as boatbuilders. There are 22 coastal villages in the Halmahera sector which were of some local importance. All of them had minor port fa- C. Mindanao sector. cilities or were ports-of-call for the Royal Netherlands Line Settlement in Mindanao was concentrated in the coastal areas steamships. and along the few lines of travel which cross the island or pene- (a) General facilities. There were radio stations at Djai- trate the interior. There were 10 principal towns, 8 of which lolo and Tobelo, a hospital at Djailolo, and numerous copra were also the principal ports. Fifty-six coastal villages had har- plantations were scattered throughout the area. In October bors or landing facilities sufficiently significant to be designated 1943, the Japanese were constructing a landing strip near the as minor ports. village of Galela and another 9 miles south of Tobelo. There Two of the major ports, Davao and Zamboanga, were stops were 2 potential landing strip sites near Djailolo and an emer- on important world trade routes and had extensive port facilities. gency alighting area for seaplanes near Galela. The other major ports as well as many of the minor ports were (b) Port facilities. Anchorage for large vessels is, in near- shipping centers for extensive trade in lumber, logs, copra, COCO- ly all cases, in open roadstead, and only small craft and proas nut products, and hemp. Lumber mill installations were located can find sheltered anchorage close in. at many of these points, and several served as shipping centers Small wharves or piers, generally with shallow depths along- for nearby plantations or food packing operations, primarily side and in most cases capable of handling only shallow-draft coconut products. The bulk of the trade from these points, how- vessels or native craft, have been located at the following points ever, was in the form of raw materials, or materials which had (unless otherwise noted, villages are on Halmahera Island): undergone only initial processing. Weda, Gamsoengi, Inggelang (Inggelang Island), Boeli-sera- Even at the minor ports many of the installations were con- ni, Lolobata, (aerial photographs indicate 3 new piers), Goeroea structed of reinforced concrete and had storage or cargo-han- (aerial photographs indicate 1 new pier), Bobaneigoe, Kaoe, dling facilities superior to those available at points in the south- Tobelo, Galela, Kjiko (Morotai Island), Djailolo, Mare (Mare west Pacific which were designated in an earlier JANIS study as Island), Ngofakiaha (Makian Island), Batoela, Waisabatang, major ports. (Batjan Island), Laboeha (Batjan Island), Penamboean (Bat- jan Island), Waja (Mandioli Island). (1) Surigao. No cargo-handling machinery or repair facilities have been The captal of Surigao Province, Surigao, was the largest and most important town on the northeastern coast of Mindanao, Unless otherwise noted, the estimates of unloading and discharging capacities of handling much of the trade of eastern Mindanao. It was the cen- ports discussed in this topic are based on short tom of 2,000 pounds of general cargo handled daily at the vessel berths, assuming an 8-hour day. *JANIS 157, Netherlands New Guines. BRIEF Page I 17 ter of extensive gold mining operations, and had lumber, corn, (b) Port facilities. The landing place for the town is lo- and rice mills. Copra was exported in quantity. cated about 1% miles northeastward from Cagayan with a good (a) General facilities. The north coastal road connected road connecting. with Davao, Cotabato, Cagayan and Placer. There was a diesel The harbor is an open roadstead near the head of the bay. The electric power plant, a radio station, and telegraph connection middle of the bay is deep and clear with anchorage available with Cantilan via Placer and Gigaquit. At Lake Manit, 18 miles in 8 to 20 fathoms of water. southwest and connected by road, was an alighting area for sea- The only facility at the port was a reinforced concrete wharf planes and about 16 miles south, also connected by road, was a about 380 feet long and 30 feet wide. In 1939 reports indicated small emergency airfield. A mill railway ran about 2 miles in- a least depth of 20 feet alongside. The wharf was lighted. land from the beach. Storage facilities included a cargo shed and a number of ware- There were 2 maternity hospitals (4 and 8 beds) and 1 dis- houses near the wharf. pensary. Repair facilities included bus company machine shops and Billeting accommodations were available in the schools, ho- garage, and several small machine shops where minor repairs tel, constabulary headquarters, provincial building, and the hos- could be made. Welding equipment, but no foundry facilities, pitals. were available. (b) Port facilities. Surigao itself is up the river and inac- Unloading capacity is estimated to have been 300 short tons. cessible to anything but very small boats. All port facilities were (3) lligan. at Bilanbilan, about 3/3 mile southeast. Iligan, on the north coast of Mindanao, handled the com- Anchorage is in Bilanbilan Bay, open to the northward, with depths of 10 to 15 fathoms. A cove in the northwestern corner merce of the Lake Lanao district. Copra and corn were the chief of the bay forms a natural harbor of limited area with depths of exports. from 4½ to 10 fathoms. Small vessels can find shelter in 9 feet (a) General facilities. The town had a 55-kilowatt diesel of water behind the harbor point. engine electric light plant, a telegraph station, and a first-aid The piers and wharves are as follows: station. Only limited billeting facilities existed. Main wharf, reinforced concrete, 325' long (face) and 29½/2' wide, (b) Port facilities. The harbor is an open roadstead depth along face, 13 feet to 30 feet. Improvements were under in the southeast corner of Iligan Bay. The anchorage off Iligan way in 1937. is bad; during the northeast monsoon it is untenable. At such Ong Hing Lian wharf, wooden, 85' long (face), 7½ to 18 feet of times vessels have sought shelter 3 miles northward of Iligan in water along face. 20 to 25 fathoms. T-head pier, 2 feet of water off head. T-head pier, no data. The only landing facility at Iligan was a reinforced concrete Pier about 100' long, no other data. pier 272 feet long and 39 feet wide, with depths alongside rang- No cargo-handling machinery was reported at any of the piers ing from 12 feet at the inshore end to 36 feet at the head. The or wharves. pier was equipped with metal bollards and fender piles, and was Storage facilities included a stone and masonry hemp ware- lighted. house at Surigao, several other warehouses at Bilanbilan, 2 oil Storage facilities included a cargo shed on the pier and 2 tanks about 20 feet in diameter and 10 to 12 feet high, at Bilan- buildings located at the root of the approaching causeway. bilan, and an open area of over 10,000 square feet backing the No repair facilities have been indicated. main wharf. Unloading capacity of the port is estimated to have been 240 Two short roadways, over 20 feet wide, connected the main short tons. A roadway connects the pier with the town. Fresh wharf with the provincial road, which paralleled the entire water could be secured from a pipe connection at the outer end waterfront at Bilanbilan and connected with Surigao. of the pier. Diesel oil was stored in bulk and piped to the waterfront. A (4) Misamis. fresh-water pipe was laid to the main wharf. The only repair facility was a small machine shop. Misamis, on the northern coastal plain of Mindanao, was the There were several tugs and a few lighters. westernmost port of importance on the north coast. It was the Unloading capacity at the main wharf is estimated to have business center for the surrounding agricultural area, a base for been 240 short tons. small motorboats, trans-shipment point for lumber, and a port of export for corn. (2) Cagayan. (a) General facilities. A 125-kilowatt electric power The capital of Misamis Province, Cagayan is the only all- plant, operated by a lumber company primarily for its own use, weather port on the northern coast of Mindanao and the termi- and a telegraph and a radio station constituted the facilities nus of the north-south road which crosses central Mindanao to located at Misamis. Adequate water was obtained by catch- the Cotabato-Davao highway. ment and from wells, a few of which were artesian. Three (a) General facilities. Facilities which have been avail- schools, a wooden military barracks, churches, and other town able at Cagayan include: A mountain stream with a capacity of buildings might provide billeting facilities. 158,400 gallons per day; a 160-kilowatt diesel electric power (b) Port facilities. The harbor, a small natural bay open plant; 2 radio stations, one 200-watt and the other 100-watt from the southeast but protected from northwest winds, has shortwave; and 3 hospitals with a total of 106 beds. The hospi- depths of 4½ fathoms at the entrance decreasing toward the tals, churches, a hotel and jail, and other concrete buildings head of the bay. with galvanized iron roofs might be available for billeting pur- Two piers were located at Misamis: the government pier, poses. consisting of a dumped rock causeway 235 feet long and 27 Page I 18 BRIEF feet wide, and a 40-foot square steel sheet-piling head, and a tended from a reclaimed area fronted by a concrete bulkhead. reinforced concrete pier section 187 feet long and 40 feet wide, A reinforced concrete boat pier extended eastward from the with reported depths alongside of 20 feet; a privately-owned approach pier and parallel to the T-head wharf. These facilities lumber mill pier consisting of a rock and earth causeway 200 had the following dimensions: feet long with a pier, probably of timber construction, extend- The T-head wharf had an 800-foot face, with depths along the ing about 250 feet seaward, with reported depths alongside outer side of 25 to 30 feet and along the inner side of 20 feet. ranging from 13 to 16 feet at low water. The latter pier was The approach pier was 465 feet long with depchs alongside of lighted, water was piped to it, and industrial tracks on the cause- 15 to 20 feet, but the eastern side was broken into 2 segments by way connected it with a lumber mill. a 178-foot boat pier extending parallel to the shore. Two govern- No special storage or warehousing facilities have been re- ment wharves running to the east and west of the base of the ap- proach pier extended for 1,180 feet along the waterfront and had ported. depths alongside of 15 feet. Machine shops capable of handling minor repairs were avail- Another government wharf extended for 300 feet to form the small boar able. Unloading capacity of the port is estimated to have been basin quay. 600 short tons. A reclaimed area had 1,970 feet of bulkhead, most of which (5) Oroquieta. was used as a quay by small boats. The water adjacent to these facilities was dredged to the depths noted. Located about 1 mile northwest of the town, Loboc Cove, There were no cranes. All cargo was handled by ships tackle the harbor for Oroquieta, has charted depths of from 3 fathoms and was hauled to and from the ships side by trucks. at the pier to 61/4 fathoms at the entrance. Anchorage, pro- The T-head wharf was lighted and water was available. tected from southerly and westerly winds, with good holding Storage facilities included a customs warehouse and at least 5 ground, may be found about 1/4 mile from shore in 12 fathoms private warehouses with a capacity of about 5,000 tons. The re- of water over muddy bottom, but during the northeast monsoon claimed section, probably available for open storage, had an area this anchorage is untenable. of about 11 acres, Harbor boats included 4 light towing launches The only landing facility at Oroquieta consisted of a dumped and 2 small sea-going tugs, owned by a commercial towing rock causeway 135 feet long and 20 feet wide with a rock-filled company, and 6 sea-going and 4 harbor lighters of 50 to 100 crib head 27 feet long and 33 feet wide, terminating in a trein- tons capacity. forced concrete pier, 194 feet long and 30 feet wide, on piling. Limited repair facilities existed, including a marine railroad Depths of 10 feet are reported along the southern face and 27 capable of hauling out a vessel of 50 tons. A machine shop for feet along the northern face. small repair work also was available. A large warehouse is reported to have been located in the Discharge capacity of the port is estimated to have been 2,420 town. short tons. Experienced gangs of native stevedores were avail- The unloading capacity of the port is estimated to have been 200 short tons. able. The discharging rate was from 15 to 30 tons per stevedor- ing gang per hour, depending on the cargo. No bunker coal or (6) Zamboanga, fuel oil was available. The only large town in western Mindanao and one of the island's most important ports, Zamboanga exported copra, coco- (7) Cotabato. nut products, hemp, lumber, and canned fish. Vessels called from Cotabato, the third largest town on Mindanao, was the center many major Pacific ports. A U.S. Army Airfield was located of trade for the Mindanao Valley and surrounding coastal area. near the town, but there were no road connections with the Rice, copra, and corn were exported in quantity, and supplies main part of the island. were available in its commercial stores. (a) General facilities. Among facilities available at Zam- (a) General facilities. A municipal pipeline water supply boanga were: a 2-diesel engine electric light power plant which system, an ice plant, a 122-kilowart electric light plant, a tele- served the town via overhead wires; a reservoir and water sys- phone system, a radio station, 2 maternity hospitals with a total tem that provided pure drinking water; a government telegraph of 12 beds, and 1 dispensary were among the facilities of the office and radio station at the airfield, a military barracks radio town. A hotel, a girls' dormitory, constabulary barracks, church- station, and 4 other radio transmitters in the adjacent area; a es, and municipal buildings might provide billeting facilities. A well-developed telephone system; and an army hospital and 3 commercial airport was located near the town. civilian hospitals. Several schools, a police barracks, military bar- (b) Port facilities. A river port, Cotabato is located on the racks, churches, 4 hospitals, and municipal. buildings might be banks of the Mindanao River about 5 miles above Cotabato En- available for billeting. trance from Illana Bay. The entrance has a controlling depth of (b) Port facilities. The harbor is an open roadstead in 5 feet over the bar. Large vessels must anchor outside and lighter Basilan Strait with depths ranging from 10 to 45 fathoms. cargo to the port. Opposite the town the river forms a basin It is protected on the south but exposed to gales from the west area of about 15 acres with depths of 5 to 18 feet over soft mud. and southeast. However, during the northeast monsoon, it is The best anchorage is in Illana Bay, northwest of the entrance, in sheltered and the water is smooth. An inner small boat harbor, depths of 5 to 20 fathoms over mud bottom 1 mile from with depths ranging from 5 to 20 feet, is formed by a rock shore. During the heights of the southwest monsoon this an- jetty and a rock breakwater. The anchorage off Zamboanga is chorage might become uncomfortable. Smaller vessels can not good. The coast drops off rapidly and outside the 12-fathom anchor closer inshore. contour the bottom is hard and uneven. The main landing facility at Cotabato was a concrete and The landing facilities consisted of a reinforced cóncrete T- sheet piling quay about 425 feet long running parallel to the head wharf, approached by a reinforced concrete pier which ex- river bank with depths alongside ranging from 7 to 14 feet at BRIEF Page I 19 low water. In addition, there were 2 small municipal wharves, Warehouses located at Santa Ana, 5 of which had a total es- one with a depth of 14 feet alongside and the other with a depth timated gross floor space of 81,000 feet, are believed to have of 4 feet. been able to handle 4,000 tons of cargo. One acre of open stor- Storage might be possible in a shed, 200 feet by 25 feet, which age space was also available near the pier. There were 2 ware- was located to the rear of the quay. Other town buildings, in- houses at Ipil and 1 at Lanang Point. cluding a storehouse for explosives, might be available as ware- Japanese sources report that a shipbuilding yard for medium- houses. In the vicinity of the quay, there was a 2-acre open space sized vessels has been established at Santa Ana. There was a that might be used for storage. machine shop available as well as casting and welding equip- Repair facilities included several machine shops with welding ment and a small private marine railway capable of handling equipment available. boats up to 40 feet. Lighters and tugs were available for the handling of cargo The discharging capacity at Santa Ana has been estimated at from the anchorage at the river mouth. Trucks had access from 450 tons. All cargo was moved by flat rail trucks from wharf to the waterfront to the inland road system. Before the war, steam- warehouses. Stevedores were available. For general cargo, the boats connected with other ports in the area and small river discharge rate was 20 tons per gang per hour. Two sea-going steamers made daily trips up the river. tugs, 15 lighters, 11 scows, and a number of fishing boats and No estimate of unloading capacity is available. launches were based in the Davao Harbor. (8) Davao. (9) Malaybalay. With its nearby port Santa Ana, Davao constituted the chief Located in the interior, Malaybalay, the capital and largest commercial center of Mindanao. It was the world's leading port town of Bukidnon Province, is on the central uplands of Minda- for the shipment of hemp and also exported copra and lumber. nao, about 66 miles southeast of Cagayan. There was a com- The largest concentration of Japanese in the Philippine Islands mercial airport 2 miles west of the town. Billeting facilities were was found within a radius of 30 miles of Davao; they controlled available in a Catholic girls' dormitory, a government resthouse, most of its commercial activity. Roads connected Davao with and the constabulary barracks, as well as in several schools. the interior; a commercial airport was located nearby. Water was obtained from a watershed north of the town. Ma- (a) General facilities. Facilities located at. Davao includ- laybalay had telegraph, radio, and telephone connections, and ed: a city water system based on a reservoir drawing supplies a provincial hospital. from springs; a 515.5-kilowatt diesel electric light plant; 4 radio stations; an urban telephone system and a second system con- (10) Dansalan. necting nearby Japanese plantations; and 6 hospitals with a to- Dansalan, the capital of Lanao Province and the largest in- tal of 282 beds. A constabulary barracks, hotel, 3 schools, terior town, was the nucleus of Moro political and social life in churches, and municipal buildings might provide considerable billeting facilities. western Mindanao and the site of Camp Keithley, the Philippine Army training camp. It is at the northern end of Lake Lanao. (b) Port facilities. Within the Davao Harbor limits, port The main road between Iligan and Cotabato passes through facilities were located at: Santa Ana, which handled the bulk of Dansalan. The town had limited possible billeting facilities, a the Davao traffic and which was linked to Davao-1 mile dis- tant-by 2 good roads; Ipil; Lanang Point, the petroleum ter- waterworks, a radio station (KZPN) at Camp Keithley, tele- minal; Tibungko, the shipping terminal of a lumber company; graph and telephone facilities, and a 105-kilowatt capacity and Tambungon. electric plant. Two hospitals with a total of 49 beds were located The harbor at Santa Ana is naturally sheltered from west to here. north and to some extent from northeast to east. During the southwest monsoon the sea is choppy. The 5-fathom contour is (11) Villages. 200 to 400 yards offshore and the approach is clear of dangers. Most of 56 coastal villages that constitute the minor ports of The harbor at Ipil is a small basin and at Lanang Point, an open Minandao are located on the river entrances, bays, and other roadstead. There is anchorage for large vessels off the Santa indentations found at almost regular intervals around the island Ana pier in depths of 12 fathoms over mud bottom. Vessels anchor in 20 fathoms over mud at Tibungko with an anchorage coastline. The remaining villages are located on off-lying small for smaller craft closer to shore. At Tambungon there is anchor- islands. The natural harbors provide sheltered anchorages, good age offshore in 10 to 20 fathoms over mud. holding ground, adequate depths, and approaches free from The government pier at Santa Ana consisted of a reinforced danger; but all 4 favorable factors are seldom found in any concrete outer section 75 feet by 326 feet and a solid-fill inner single harbor. section 75 feet by 238 feet, with steel sheet-piling along one Generally, the villages served as shipping outlets for hemp, side. Depths at the end of the pier were 25 feet. The pier was copra, coconut products, or lumber. In many cases they were lighted and fresh water was piped to it. Locations of other piers closely tied in with local logging, sawmill, or coconut proc- were: a small pier at Ipil; two 200 feet wharves, one open tim- ber pile and the other concrete, at Lanang Point; a small timber essing operations. Utilities, communications facilities, supplies, pier, the terminus of a logging railway, at Tibungko; a 1,300 and general and repair facilities frequently were very meager; foot stone pier with a depth of 15 feet at its end at Tambungon, where they did exist, they were available only to the degree the terminal of a logging railway. One wharf at Lanang Point necessary to take care of local commercial operations. TABLE had a 1-ton crane and pipelines to oil storage tanks. I 2 lists port facilities that were available at coastal villages. Page I 20 BRIEF TABLE I 2. PORT FACILITIES LOCATED AT COASTAL VILLAGES ON MINDANAO AND NEARBY ISLANDS* DEPTH ALONGSIDE VILLAGE TYPE HARBOR PORT FACILITIES PIER OR WHARP EXPORTS Mati Bay Reinforced concrete pier with T-head landing 39.5' wide Low water 20" at head Hemp and copra and 147° long, extending from 530' rock and earth cause- way. Hinaruan River entrance Small landing along bank. Charted at 2 fathoms Port Lamon Bay L-head wharf extending 1,000' from shore DO near 5-fathom At face, 24' to 28' Lumber curve. Head 150' long and 15' wide. Wharf lighted. Minor repair facilities available. Tandag Small cove Small boar stone pier. Cargo landed on beach. At pier, 6' Lakando Open roadstead on Mining company timber T-head pier áttached to 400' cause- (Masapelid L) side of bay way. Head 80' long. Two small sheds on causeway and larger building on outer end. Pier lighted. Narrow gauge track ran to end. Pipeline on pier indicated. Placer Cove Rock and timber pier 20° wide and 402' long, extending Controlling depch, 16' Shipping point from 345' rock causeway. at low tide for mining area Numancia Channel Scone pier. 31/2 fathoms charted (Siargao I.) near end of pier Dapa Cove Reinforced concrete pier 30' wide and 115' long, extending At end main pier, 20' (Siargao 1) from 450' rock causeway. Another smaller pier. Dinagar Cove Pier At end, 3' to 5' (Dinagar I.) Butuan River port Main landing platform with timber deck 31' by 72' and Along face main land- Hemp and copra apron along face. Cargo shed on landing 21' by 43'. Second ing controlling depth, small boar landing entirely covered by shed. 14' Nasipit Opening berween L-bead pier 150° long and 40' wide at end of 375' cause- bluff rock headlands Pier end in deep water way and 100' extension. Copra and logs Odiongan Open roadstead near Lumber company T-head pier 350' face. Company operated At face, 30' Lumber bay head 18.6 mi. of railroad and had 3 locomotives. Water piped to pier end. Gingoog Open roadstead near Open timber pile L-head pier with wood deck extended 400' Lumber bay head from shore. Face of L-head about 230' long. Pier lighted. Tracks on pier. Lumber company had 2.5 mi, of railroad. Balinguan Bay Small pier used as ferry landing extended 450° from shore. At end, 8' Ferry connected with Binone on Camiguin 1. Binone Open roadstead Small pier for ferry landing. (Camiguin I.) At end, 6' Mambajao Open roadstead 1,000' stone causeway and timber pier extensión 30° wide (Camaguin I.) At end, 14' Hemp and copra at outer 115'. Small cargo shed on mid-pier. Open storage Alongside, 6' to 15' space also available. Water piped to end. Bugo Open roadstead near Rock causeway with timber T-head wharf face 200' long. bay head At face, 30' Railroad tracks connect packing plant with face of pier. Pier lighted. Kolambugan Open roadsead in bay Lumber company wharf, 1,950' long made of wood piling At end, 25' Lumber with wood decking. Tracks on pier. Wharf lighted. Machine shop at mill. Jiminez Open roadstead Rock and earth causeway with reinforced concrete pier, 39.5' At head, 20' wide and 275' long, at seaward extremity. Warehouse avail- able. Plaridel Bay Two wooden landings, each 20" wide and 65' long. Rein- At head concrete pier, forced concrete pier 30° wide and 65' long added to 1 land- 13'. At timber wharf, ing. 16' Baliangao Bay Dumped rock causeway 20' wide and 120' long, with rein- At head, 10' forced concrete pier at end 29.5' wide and 165' long. Also small boar stone pier. Porr Puluan Open roadstead on Dumped rock causeway, 200' long and 20' wide, with steel bay side At head, 27' Copra, corn, sheer-piling 32' long and 30° wide, ending in concrete pier 130' long and 30' wide. hemp, lumber. BRIEF Page I 21 TABLE I 2 (Continued) DEPTH ALONGSIDE EXPORTS VILLAGE TYPE HARBOR PORT FACILITIES PIER OR WHARE Port Santa Practically landlock- Timber pier 150' long and 100' wide. Several sheds and At end, 11' to 15' Lumber Maria ed mill buildings. Tracks from wharf to mill. Caldera Bay Bay Coconur company had 2 small timber wharves. Sheds, ware- At ends of wharves, Coconut products houses, tanks on shore. Pipeline to wharf. Small marine rail- 28' and 14' way but no machinery. Kabasalan River port Timber wharf. 10' Lumarao Bay Timber pile bulkhead inaccessible to boats having draft Lumber more than 10°. Wharf lighted. Railway tracks connect wharf and lumber mill. Small tug and several lighters were avail- able. Number of sheds and mill buildings. Minor repair facilities. Naga-Naga Open roadstead at Open pile and timber T-head pier 390' across face and 50' At T-head, 19' to 24' Lumber bay entrance wide. Tracks on pier connecting with mill. Water piped to pier. Pier lighted. Malangai Bay Reinforced concrete T-head pier, 160' long and 40' wide, at At face, 27' low water Coal extremity 200' causeway. Belt conveyor for direct coal load- ing. Small warehouse and sheds. Radio station and diesel generator. Margosatubig Bay Lumber company pier, T-head, 180' long and 30' wide, with At face lumber pier, Lumber approach 60' long and 30' wide. Municipal wharf with T- 20'. At face municipal head 40' long and 20' wide. Motor launches available. Water pier 10'. on municipal wharf. Logging railroad 7.1 miles long. Flecha Point Small bight Timber T-head wharf. Water piped to pier. At face, 13' to 35' Lumber Pagadian Bay Rock and earth mole 6' wide timber landing at end. Also No water at end of small stone landing. mole at low tide Malabang Open roadstead in Small boar landing. Shed. Copra bay Parang Natural harbor L-shaped pier with 564' causeway approach and reinforced At face, 4' to 30' concrete pierhead 39' wide and 300' long, Makar Cove Small boar landing, 50' long and 20' wide. Glan Cove Reinforced concrete pier-head, 82' long and 291/2' wide, At face, 12' to 18' Copra and hemp connected to causeway. Lawa Open roadstead on Open pile and timber pier, 300' long. At end, 3' gulf Malita Open roadstead on Open pile timber pier 250' long and 30° wide. Plantation At end, 9' Hemp and copra gulf warehouses and open storage space. Lacaron Open roadstead on Small launch landing. gulf Daliao Open roadstead on Timber pier 600' long. Railway served pier. Water piped to At end, 14' gulf mid-pier. Travelling 15-ton motor operated crane was avail- able. 3 large warehouses and open storage. Minor repairs. Talomo Bay Open-pile timber pier 350' long. Outer end widened. Large At end, 13' to 18' warehouses and open storage. Madaum River port Pier 20" wide and less than 100' long. Monserat Cove Small concrete pier. At face, 13" *The ports of Basilan Island are shown in Table I 3. D. Sulu Archipelago. for detachments of the Philippine Army, the hub of Moro cul- The greater part of the population in the Sulu Archipelago is ture, and the home of the Sultan of Sulu, the political and reli- concentrated on Jolo and three or four of the small islands im- gious leader of the Moros. mediately south of it. Jolo was the most important port and ad- (4) General facilities. A water system, a 240-kilowatt ministrative and commercial center of the island. Malaria, diesel electric power plant, a commercial radio station and an dengue fever, and dysentery were prevalent. army station, a manual telephone system, a 46-bed hospital, and (1) Jolo. a 40-bed treatment station were among the facilities at Jolo. A The capital of the Sulu Province, Jolo was the headquarters school, military headquarters, hospital, sultan's palace, church, Page I 22 BRIEF and several other buildings might be used for billeting. Sea- (b) Port facilities. TABLE I - 3 lists facilities available at planes could land and take off in Jolo Harbor; an emergency the 9 villages. airplane landing field was located near the city. (b) Port facilities. At least 5 first-class berths were avail- E. Northeast Borneo. able in 73 to 84 feet of water. The entrance channel is clear and The few towns in this sector were commercial and administra- the port is sheltered from the southwest, but fairly open in other directions. tive centers and, with the exception of Beaufort, were ports. There were 2 piers: the principal one, a concrete structure at Most of the natives live in villages or hampongs, generally lo- the end of a stone causeway, had a seaward face of 280 feet and cated along the rivers on the seacoast. a depth alongside of 30 feet; and the Chinese pier, a wooden structure. The bottom dries alongside the latter at low water. (1) Jesselton. There were no cargo handling facilities. Fresh water was piped With a population of 4,594 (1931), Jesselton was the chief to the pier. port on the west coast of British North Borneo and the northern A cargo shed on the main pier and warehouses in the town terminus of the State Railway. It was the focal point of the best had a capacity of 30,000 tons of cargo. road system in Borneo and a center of agriculture and rubber- A small marine railway capable of handling launches up to growing. 50 feet and 2 small machine shops for minor repairs were avail- able. (a) General facilities. Among the facilities at Jesselton Privately owned gasoline launches and native boats, but no were the following: tugs or lighters, were located at Jolo. A public water supply system with a reservoir which supplied 34,350,600 gallons in 1939. (2) Villages. A radio station. The 9 coastal villages of the sector were minor ports used as A diesel-powered electric power plant AC and DC, 366KW, shipping points for lumber, copra, and rubber companies. 230 volts. (a) General facilities. There were small radio stations at An automatic telephone system within the town, connecting with long distance lines to many interior points. Siasi, Bangao, and Cagayan de Sulu, a telephone system on Basi- Overland telegraph lines to Beaufort, Tenom, and Mempakul. lan Island and a few small hospitals and dispensaries were scat- A well-equipped 66-bed hospital. tered throughout the sector. Siasi had a small electric power An ice plant. plant and a fair seaplane anchorage. Billeting facilities were lim- Two garages and the State Railway locomotive repair shop. ited. Ample billeting and warehouse facilities. TABLE 1 - 3. PORT FACILITIES OF MINOR PORTS OF THE SULU ARCHIPELAGO DEPTH ALONGSIDE PIER OR HANDLING VILLAGE HARBOR PIER OR WHARE WHARF EXPORTS CAPACITIES Isabela Room for 2nd class vessels, pro- Wharf with 200' berthing 18' to 29' Lumber 70,000 feet of lumber per hatch rected except NE space Fresh water Small pier 12' General per 24-hour day No estimate Port Holland Well-sheitered but size permits Wharf 513' long. Fresh water 17" to 29' Lumber 500,000 feet of lumber per 24 only small vessels piped but capacity small Wharf hours 55° long 6' General No estimate Kulibato Exposed to N, NE, and E Pier 40' long 21' General No estimate Point (Lamitan) Tandu Fair shelter, 11' to 32' depths Stone mole 6' General 'No estimate Bato Siasi Mid-channel, in depths 36' to Government wharf 47' long. 20' General No estimate 60' Fresh water piped. Bangao Excellent shelter but limited Wooden pier 50° long. 18' General No estimate space. 22' to 42' depchs. Si Tangkay Open Concrete wharf, 98' long, 65' 18' General No estimate wide New Baru Baru Baru Bay. 36' to 60° Small pier, in poor repair in 16' General No estimate Baru depths close in. 1937 Cagayan de Sulu Small land-locked harbor. An- Pier with 131' of berthing 13' Copra No estimate chorage outside in 54'-66' space depths. Small quantities of provisions could be obtained at Isabela, Port Holland, Lamitan, Siasi, Sitankai, New Baru Batu, and Cayagan. Isabela, Port Holland, and Lamitan maintained small stores of gasoline and diesel oil. The lumber company at Port Holland had a large machine shop which could make minor marine repairs. BRIEF Page / 23 (b) Port facilities. The harbor, partly open to the north Food supplies could be obtained in small quantities. Engi- and about 2,400 feet wide off pier end, can accommodate vessels neering and deck supplies were obtainable. A stock of 160,000 up to 7,000 tons. Dredging is necessary to maintain depths. gallons of gasoline was maintained. Fairly secure anchorage for 30 or 40 vessels can be had in nearby Twenty-six lighters with a total capacity of 8,000 tons were waters. available for loading ships anchored in the stream. The only pier was a reinforced concrete, L-shaped structure, The discharge capacity is estimated to have been about 450 providing berthing space of 328 feet, with depths of 18 to 26 short tons per day. feet alongside. The pier was electrically lighted and there were several cranes with capacities up to 20 tons. Railway tracks ran (3) Linghas (Tarakan). to the pier. There were also several small docks, dry alongside at This was the port for exporting the petroleum product at 2 low water. nearby fields. The 1930 population of the town was 11,589; of Three warehouses at the pier had a total floor area of 67,500 the district, 13,398. Food was almost wholly imported. There square feet. was an airfield and a seaplane alighting area. Boiler water was piped to the pier with connections at each (a) General facilities. Most of the facilities in the Lingkas berth. Maximum flow was 15 tons per hour. area were owned by the oil company. Among them were: Fresh provisions were plentiful. Deck and engineering sup- plies were available in limited quantities. About 7,000 gallons A radio station. of gasoline were kept on hand in drums and tins. A telephone system connecting various parts of the oil fields. A modern hospital of 120 beds. There were no ships' repair facilities but the railway shop Two electric power plants. was available. A machine and repair shop at the Pamoesian oil field. Discharge capacity is estimated to have been about 340 short A pumping station which provided water from a stream for tons per day. purposes other than drinking. Drinking water was obtained by rain carchment. (2) Sandakan. An ice plant and distillery. The largest town (1931 population, 13,723) and chief port, A narrow-gauge railroad connected Lingkas with the Pamoesian oil field. Sandakan was also the capital of British North Borneo. It pro- Good roads connected with the airfield and with the oil fields. vides a good emergency seaplane alighting area and anchorage. Billeting facilities were very limited. (a) General facilities. The important facilities were as follows: (b) Port facilities. The harbor was secure in all weather. A radio-telegraph station of 21/2 KW. There were reported to be 12 to 15 berths (1,800 feet) in 42 A steam electric power plant, 3 phase, 60-cycle, 700 KW at feet of water and many berths in 24 to 30 feet. An anchorage 110-220 volts. north of Lingkas could accommodate a large number of destroy- An automaric telephone system with 200 subscribers. ers or submarines. A waterworks system supplying a daily minimum of 180,000 There are 2 piers, as follows: gallons of filtered and sterilized water. An ice and aerated water plant. 1. T-head pier, 1,050 feet long with low-water depth at head A closed sewerage system. of 30 feet. Pier was 6 feet above water at high tide. Water was A well-equipped 90-bed hospital. piped on with a 3-inch connection. Two 6-inch and one 4-inch Extensive billeting facilities. fuel oil lines with standard firrings connected with the oil field. A Two warehouses for storage, totalling about 12,000 square feet good road, 5 miles long, led to the oil fields. of area. 2. T-head pier, 1,362 feet long with a low water depth of 33 A small foundry and machine shop. feet along face. Pier was 6 feet above water at high tide. Water was (b) Port facilities. The harbor gives excellent shelter and piped on with a 3-inch connection. Two 10-inch and one 6-inch fuel oil lines with standard fittings connected with the oil fields. A has room for about 40 first-class berths in depths of 30 to 54 narrow-gauge railroad, laid onto the pier, led to the oil fields. A feet. A bar across the entrance has limiting depths from 8 to 10-ton crane was mounted on tracks. Boat hoisting gear was 30 feet at low water. capable of lifting a 50-foot launch. There was only 1 important wharf, the property of the government. It was substantially built, 450 feet long, 44 feet A floating crane of 15-ton capacity was moored between the wide for a length of 225 feet, and had a depth alongside of 19 2 piers. feet at low water. The wharf had electricity, a water hydrant, There was an oil tank farm close to the shore and a ware- and a small narrow-gauge railway nearby. Twenty-foot wide house, 60 feet long. was built at the end of the north pier. asphalt roads connected with points several miles around, and A pump house on the north pier could supply salt water for 1 road ran for 17 miles into the interior. A narrow-gauge rail- fire fighting. way for timber ran 8 miles into the jungle. No gasoline was produced at Tarakan. The maximum dis- A second pier had a depth of 11 feet at the head and was charge rate for fuel oil at both piers, working simultaneously, equipped with a 15-ton fixed hand crane. was 7,200 pounds per hour. The south pier alone could dis- In addition, there were 4 small jetties, privately owned. charge 4,800 pounds per hour. Discharge was by gravity, forced There was a patent slip belonging to the British Borneo Tim- feed, or both. ber Company, 400 feet long, with a cradle 150 feet long, draft Food was available in small quantities. on keel blocks of 5.6 feet forward and 10.6 aft, and having a The only repair facilities available were at the oil field ma- lifting power of 500 tons. chine shop. A small shipyard and foundry could build lighters up to 100 The discharge capacity for general cargo is estimated to have tons displacement. been about 225 short tons per day. Page / 24 BRIEF 200-ton slipway, a fitting and turning shop, a carpenter shop, (4) Villages. and a smithery. There were 9 coastal villages of local importance and 1 The government maintained a small wrecking tug. There inland town, Beaufort, was an administrative headquarters and were also 24 lighters of 4 to 15 tons capacity and a steam water- the center of a rubber and sago-producing area. All of the coastal boat of 18 tons capacity. villages had some minor port facilities, including 1 or more Warehouse storage space totalled 40,000 square feet. small piers. Storage areas for gasoline had a total capacity of 450,000 Kudat, a livestock center, had a radio station, telephone and barrels, and for diesel oil, 2,100 barrels (1936). No pumps telegraph systems, a submarine cable to Singapore, a water sup- were available, but a portable pipeline was used. ply system, and a 28-bed hospital. Tanjong Batu was connected by a railroad 3 miles long with a (2) Gorontalo. manganese mine. The second largest town of northern Celebes (1930 popu- Lahad Datu, a tobacco and copra shipping point, had tele- lation, 15,603), Gorontalo was the trade center for the Gulf phone and telegraph connection with Sandakan, and a 10-mile of Tomini area. Although 483 vessels of a total tonnage of long light railway led to a tobacco plantation. 594,000 visited the port in 1939, port facilities were poor. Lake Tawau, the center of a large trade in rubber, coconuts, live- Limboto was a seaplane stop of the K.N.I.L.M. and the Dutch stock, and timber, was also the headquarters of a large-scale had planned a landing strip which may have been built by the tuna-fishing industry. There was a radio station, a telephone Japanese. Good roads connected with localities as far away as system, and a civil hospital. 25 miles. Tanjong Selor, Tanjong Redeb, and Benoa Baru had radio (a) General facilities. Facilities at Gorontalo included the stations. following: A radio station. F. Northern Celebes sector. A local telephone system. The Minahasa region around Manado is densely populated Telegraphic cable to Kema. with numerous villages and several large towns. The remainder An overland telegraphic connection with Koeandang. An electric power plant with a 400 horsepower diesel engine. of the sector is largely unexplored wilderness with no towns and A government hospital with 44 beds. a few primitive widely scattered villages. (1) Manado. (b) Port facilities. Anchorage in Gorontalo Bay is poor The largest town in the Celebes Sea area (1930 population, because of great depths, confined space, and strong currents. The 27,544), Manado was the commercial hub for the Celebes, river is navigable only by the smallest craft. Large vessels tied Sangihe, and Talaud Islands, and part of the Moluccas. Although up to mooring buoys in the bay and were serviced by lighters 486 vessels with a total tonnage of 1,875,000 visited the port in which unloaded at the small wharves on the west shore. 1939, there were no docking facilities and the vessels were serv- Lighters were available, but no tugboats. iced by praus. Motor roads connected with important places in Minor motor repairs could be done at an automobile repair the surrounding area. There was a landing strip, connected by shop which had welding equipment and a lathe. road, 32 miles south, and another was under construction by the Storage facilities consisted of several warehouses of the Dutch, 7 miles east. There was a seaplane stop on the K.N.I.L.M. steamship company and oil and gasoline storage installations of route at Lake Tondano. the Shell Oil Company. Capacities are not reported. (a) General facilities. Among the important facilities (3) Tondano. were the following: The chief inland town in Minahasa (1930 population, A radio station, call letters PKY. 15,007), Tondano was the center of an intensely cultivated re- Submarine cable to Balikpapan and Java. gion and was used as a health resort by Europeans. Two motor Telegraph line to Ternate, Gorontalo, and Kema. roads connect with Manado by different routes. Facilities included A local telephone system. An electric power plant with 3 diesel engines of 300 horsepower a radio station (PKL, PNL), a government hospital, a mission each, lighting 10 miles of streets. hospital with 36 beds, a school, and a hotel. A municipal water system with 14 miles of pipe, serving 1,491 private consumers, 113 services and plants, and 40 public hydranes. (4) Villages. The total distribution in 1939 was 37,000 cubic meters. Villages of local importance include the following: A modern, European-scaffed hospital of 124 beds. A military hospital of 8 beds. A mission hospital, and a leper asylum. Tolitoli, a minor port, had a radio station, a small water system Billeting facilities were extensive. and an emergency landing place for seaplanes. Koeandang (Kwandang), a minor port, had road connection (b) Port facilities. From December to February the an- and reported telegraph and telephone connection with Gorontalo. The Manado-Balikpapan cable landed here. chorage in the open roadstead was unsafe and Kima, to the Amoerang, a minor port, has a sexplane alighting area and had north, and Kema, to the south, were used instead. A basin for road connections with Manado and with Lake Tondano, praus, with a 210-foot wharf, was used by unloading craft draw- Tomohon, an interior village, had a modern 130-bed hospital. ing no more than 6½ feet. The basin was served by a 1-ton Kakas, on Lake Tondano, was the site of the Durch Air Line crane. seaplane base and the Durch naval seaplane base was nearby. A There were 2 small shipbuilding and repair concerns. One landing strip was 5 miles southwest. Good roads led to the landing strip and to Tondano. had 3 slipways for 200-, 100-, and 50-ton vessels, a repair yard Talise (Talisei), a minor port, was a small coaling station. workshop, a carpenter shop, and a smithery. The other had a Lighters could supply 200 tons per day. There was an emergency BRIEF Page I 25 seaplane alighting area and small stores of aviation gasoline were maintained. the Minahasa region around Manado. A second important road Kema, a minor port, was used as an alternate port for Manado, system centers on Gorontalo. 30 miles distant, during the northwese monsoon, December to February. A motor road connects the 2 ports. There is an emer- (3) Water transport. gency sesplane alighting area 5 miles northeast. Vessels of the Koninklijke Paketvaart Maatschappij (Royal Tomini, Toeladenggi (Tuladenggi), Tilamoeta (Tilamuta), Packet Navigation Co.) paid regular calls at ports in Halma- Kotaboena (Kotabuna), Totokrata (Totok), Soematata (Suma- hera, the Sangihe and Talaud Islands, Dutch Borneo, and North- lata), Tang, Boeol, Kampoengbaroe, and Stadang were minor ports and ports of call of the K.P.M. ern Celebes. Ocean-going vessels called at Zamboanga and Da- vao in Mindanao; the bulk of the island's trade, however, was carried by interisland steamers, which made irregular stops at a number of other smaller ports. Much of the coastal trade was 15. Transportation and Communi- carried on by launch-towed barges and praus. The Sulu ports cations were connected by steamer with Mindanao and Singapore. The 7 major ports of British North Borneo were served by the Straits Steamship Company and the Sabah Steamship Company, as well No portion of the Celebes Sea region has a well-developed as by others. system of transportation or communications. The areas best Inland water transport was not extensive in Halmahera or served are the Philippines, British North Borneo, and portions the Sangihe and Talaud Islands, where bars at the river mouths of Northern Celebes; Mindanao and the Minahasa district of and swift currents made navigation difficult for all but small Northern Celebes have good road systems, and 125 miles of praus. In Mindanao, however, the 2 large river systems (the railroad exist in British North Borneo. In general, however, land Agusan and the Mindanao) are used extensively for inland routes are undeveloped, and water is by far the more important transport. The rivers on the islands of the Sulu Archipelago are means of transportation. short, but used wherever possible because of the scarcity of The 60 radio stations in the region, concentrated largely in roads. The rivers of Borneo were the region's main routes of Mindanao, Sulu, and British North Borneo, constituted the travel and trade. Travel by inland waterways is relatively unim- principal means of rapid communication. Rudimentary tele- portant in Northern Celebes, except in the lakes of the interior. graph and telephone systems in Mindanao, British North Bor- neo, and Northern Celebes connected the chief cities with their B. Communications. hinterlands. Five submarine cables linked parts of the region with neighboring areas. (FIGURES I- 1 to 4) (1) Radio. There were about 60 radio stations in the Celebes Sea region, A. Transportation. constituting the chief means of rapid communication. The sta- tions in the Netherlands East Indies portion were owned and (1) Railroads. operated by the government, with headquarters in Java. Only The State Railway of British North Borneo is the only com- the Tondano station may have been of the broadcast type. The mon carrier railroad in the Celebes Sea region. It has a total stations in Mindanao and Sulu were almost all operated or con- track length of 125 miles, is of meter gauge, and runs from Jes- trolled by the Bureau of Posts to supplement the telegraphic selton to Tenom via Beaufort, with branches from Tenom to communications. None of them was of the broadcast type. North Melalap and from Beaufort to Weston. All other roads in the Borneo had 6 radio-telegraph stations; the 1 at Sandakan was region are light railways, including the short marine railways at a broadcast station, communicating with Hong Kong and Japan. the major ports, numerous logging railways, an abandoned coal mine line, and a Decauville railway serving the Tarakan oil (2) Telegraph, telephone, and submarine cable. fields. The only telegraph and telephone networks in the Dutch portion of the Celebes Sea region were in the Minahasa Dis- (2) Roads and trails. trict of Northern Celebes. Submarine cables connected Ternate The stage of development of the land routes varies from sec- with Kema and Menado with Balikpapan. The northern coastal tor to sector within the region. Mindanao has the best system, towns of Mindanao, from Gingoog, Misamis Oriental, to Kati- with 2,176 miles of improved roads, of which the best are on punan, Zamboanga, were connected by telegraph. Another line the north coast, in the Bukidnon and Cotabato valleys, and in extended southward through Dansalan and Malabang to Cota- the Davao region. Halmahera has no roads, but many foorpaths bato. The system was supplemented by radio-telegraph and tele- and some bridle paths and cart tracks. The Sangihe and Talaud phone. Mindanao had no overall telephone system, but a num- Islands are well supplied with roads, which the Dutch classified ber of provincial lines and local systems supplemented the as "secondary." In the Sulu Archipelago, Basilan Island, Tawi- radio and telegraph facilities. The only telephone lines in the tawi Island, and Cagayan Sulu Island have 1 road each; Jolo Is- Sulu Archipelago were on Basilan and Jolo Islands. The 2 land has an extensive network of gravelled, macadam, and coral submarine cables in Mindanao connected Misamis with Titunod rock-surfaced roads. All the islands have numerous trails. British North Borneo had 340 miles of roads and 640 miles of bridle and Baliangan with the island of Negros. British North Borneo paths in 1941; the west coast was much better supplied than had 700 miles of telegraph lines making up 1 main line and a the east coast. The only roads in Durch Borneo were on Tara- number of branches. A cable connected at Labuan with the kan Island; footpaths were the only means of land transport on Eastern Telegraph Company submarine cable to Singapore. the mainland. Northern Celebes is comparatively well supplied There were also 12 telephone exchanges, 2 of which, at San- with roads and footpaths, with the main roads concentrated in dakan and Jesselton, were automatic. Page I 26 BRIEF 16. Resources and Trade ploited. Japanese propaganda has emphasized the discovery and (FIGURES 1 to 4) development of a variety of minerals, particularly in Borneo. One large unexploited deposit of iron ore was in the northern A. Food resources. tip of Surigao Province, Mindanao. Much smaller deposits were reported in Beitish Borneo. A small amount of chromite has been No surpluses of food exist in the Celebes Sea area, which pro- mined on Dinagat Island off Mindanao. Mindanao had import- duces quantities barely sufficient to feed the local population ant gold mines; silver was mined as a by-product. These metals and has been obliged to import food from other parts of south- were mined primitively and on a small scale in northern Celebes, ern Asia. The staples of the native diet are rice, corn, sago, tuber- where some sulphur was also produced. tables, and nuts, some of which grow wild. Food crops were ous roots, and fish, supplemented by many tropical fruits, vege- (2) Fuels. grown on small plots of land; the few large plantations in the Ample wood for fuel exists throughout the area. Bituminous area were devoted to crops for export. A moderate amount of coal was mined in British Borneo, Dutch East Borneo, and Min- livestock was available throughout the area. Most cattle were danao; the production in Dutch Borneo (300,000 tons annual- used as beasts of burden. Goats were common in Mohammedan ly) far exceeded that in the other 2 regions. The chief source of villages and pigs in non-Mohammedan ones. The carabao was petroleum was Tarakan Island, off Dutch East Borneo, which used both for food and as a beast of burden in Mindanao. Fish produced about 4,000,000 barrels of crude oil annually before were plentiful and a more important source of food than meat, the war. The oil, which can be used as under-boiler fuel without ranking after rice, corn, and sago as a staple. There were ice refining, could be piped directly to ships lying at the piers. The factories on Jolo Island in the Sulu Archipelago and in northern Japanese have restored the field and are using it. Celebes, British Borneo, and Mindanao. British Borneo had sev- One oil seepage has been found at Banasilan, in eastern Cota- eral rice mills. Mindanao had the largest food processing facili- bato Province on Mindanao, and others have been noted in ties, including a Japanese tunafish cannery, a pineapple cannery British North Borneo. Coconut oil is used for cooking and light- at Bugo, and several small plants for making desiccated coconut. ing by natives in Halmahera, Sangihe, and Talaud. Another Japanese fish cannery was at Manado. (3) Agricultural and marine materials. B. Water supply. Timber is one of the area's principal resources. Extensive log- The Celebes Sea Area has, in general, fairly abundant water ging of numerous hard and soft woods has been carried on in supply, owing to the heavy and evenly distributed rainfall and Mindanao and Borneo. Gums and resins were collected in the numerous rivers and streams. In the eastern part of the Jolo significant quantities from the forests in British and Dutch Bor- Island group of the Sulu Archipelago the supply is sometimes in- neo, the Sulus, Mindanao, and Halmahera. Rubber was an im- adequate. Mindanao and Sulu have a number of artesian wells. portant export from Borneo, although international restrictive The surface wells are generally open and unprotected, and agreements kept production far below capacity. Small amounts should be considered polluted. Natives obtain their water from were also grown on Mindanao and Basilan Island. Coconuts shallow wells, springs, streams, lakes, and rainwater catchment were grown for local use and export (as copra and coconut oil) basins. In some places the natives pipe water to their houses on small native farms throughout the area. Large amounts of from the nearest spring through a split bamboo aqueduct. There excellent hemp were grown on plantations in Davao Province, are a few public supplies in the area and before the war, water Mindanao, in other parts of Mindanao, and in the Sulus. One ex- from these could be consumed without additional treatment, but perimental cinchona plantation existed in Mindanao. it is doubted whether the Japanese have continued adequate supervision. Reservoirs, rain water catchments, storage tanks, E. Manufacturing plants. etc., most frequently are used. All water in the area, regardless The only manufacturing plants in the Celebes Sea area were of source, should be boiled or chemically purified. Stream water small installations connected with the primary processing of should be taken from a point near the headwaters. foods and agricultural and mineral products for export. Some of the larger towns in Mindanao, Celebes, and North Borneo had C. Construction materials. small machine repair shops. Wood for construction is generally available throughout the Celebes Sea area; excellent supplies exist on Halmahera and F. Electric power. Mindanao. Rattan and the leaves of various palms can be used Information on power plants in the Celebes Sea area is in- for roofing native huts. The Japanese have recently claimed to complete. Mindanao had 20 public plants and numerous small be constructing a cement factory in northern Celebes. Coral private plants connected with mines and sawmills. The Sulus from the shores of the entire area and basalt rock from the in- had 1 very small power plant at Jolo; there was another on Ter- terior of Mindanao and the Sulus can be used to build roads and nate Island, off Halmahera. At least 2 others existed in northern airfields. Celebes, at Manado and Gorontalo. D. Industrial raw materials and primary processing. G. Commerce. (1) Minerals. The chief imports to all parts of the Celebes Sea area were Relatively small amounts of a few important industrial raw cotton goods, small iron and steel manufactures, medicines, and materials were mined in the Celebes Sea area before the war. some canned goods. The chief exports included: petroleum, coal, Large parts of the area had not been adequately surveyed for and timber from Dutch Borneo; rubber, timber, and copra from mineral deposits, and deposits in other sections had not been ex- British Borneo; Manila hemp, copra, and gold from Mindanao; FIGURE I I JANIS 155 ⑉ PHILIPPINE ISLANDS MINDANAO AND SULU DINAGAT L To METALLED ROAD TELEGRAPH STATION PRINCIPAL ELECTRIC UNSURFACED ROAD TELEGRAPH LINE POWER PLANT entimage PRINCIPAL MARITIME ROUTE SUBMARINE CABLE SAWMILL (Cutting 20,000 BOHOL 11 BIARGAO . I day and over) MAIN INTER-ISLAND ROUTE RADIO STATION GOLD MINING AREA MINOR INTER ISLAND ROUTE PROVINCE BOUNDARY SELECTED BRIDGE Numbers and CHROME MINING AREA MINDANAO SEA BUCAS GRANDE 1. letters refer SELECTED PERRY to text COAL MINING AREA Centran CAMIGUIN IL BUTUAN Lenute MISAMIS ORIENTAL 100° III IN Sway 5.6 SURIGAO Time 1 - Cargo / j AGUSAN Capital s Him Capayer also DETAILS OF SHADED AREA ARE SHOWN ON MAIN MAP indengen BASILAN ZAMBOANGA / AO BUKIDNON Cannel Maria Spitan 4, LANAO / à DAVAO TAWITAWE ILLANA BAY Name SULU ARCHIPELAGO 6° Maistang Lumerso, Vital SECURITY # - Canage Membiling Tengkey MORO GULF Patale Expenses - gri Cross Mayo I Magandy MALAMA LAKE - Date BULLIAN BASIAN COTABATO Beheiebong / GULF DAVAO Malita o SULU 8 Milk Kononadal Morker 9. à IOIO DECLASSIFIED To AUSTRALIA To AUSTRALIA By Authority of LAPAC JCS : By SR Dat 3 1 1975 131° 123° 1347 If of - = FIGURE I.L Mindanas and Sule-Transportation, Communications, Industrial Facilities. DECLASSIFIED By Authority of JCS letter, 7-25-75 FIGURE 1 - 2 JANIS 155 By SR Date JUL 31 1975 Kata i NORTHEASTERN Tandlong BORNEO 90 d' KIMANIE BAY to 100 150 with LABORR N 190 180 ELOMETERS BRUND BAY 116° ne SOUTH - TRANSPORTATION CHINA - SULU PAISAN ser : Pin SEA Longkon ROAD SEA Kota Belud BRIDLE PATH LABUR - - SAI BASSE FOOTPATH Refuren LANDARAN - due RAILROAD MP Long NORTH Beaufor Kaningen due SAT Labed Date COMMUNICATIONS Komebong BORNEO SAIVE P TELEGRAPH LINE Peniengen Selimpopan Reported) TELEGRAPH STATION + NAMEOR TELEPHONE LINE - , adtra RADIO STATION CELEBES SUBMARINE CABLE DUTCH Tal INDUSTRIAL FACILITIES SEA 5 POWER PLANT 5 1a Reclete SAWMILL - o RICE MILL BORNEO E CUTCH FACTORY OIL WELLS 1 (PUMPED FOR BUNKERING) o RAILROAD REPAIR SHOPS I COAL MINING AREA e' 116 - - FIGURE 1.2. - Nortbern Borneo-Transportation, Communications, Industrial Facilities. FIGURE I 3 JANIS 155 - - - IMP OF COMMONWEALTH OF THE PHILIPPINES NORTHERN CELEBES AUTOMOBILE ROAD RADIO STATION TALAUD EIL. SECONDARY ROAD (USUALLY MOTORABLE POSSIBLE RADIO STATION IN FAIR WEATHER) TRAIL LAND TO AIR RADIO SENDING AND RECEIVING STATION LOCATION OF INSET TELEPHONE EXCHANGE TELEGRAPH STATION LOCATION or MAP 0 POSSIBLE TELEPHONE EXCHANGE ELECTRIC POWER PLANT MAINAMERA SANGIHE EIL op o 50 100 - 8 CELEBES MILES SANGIHE AND o 50 100 TALAUD ISLANDS - KILOMETERS a ⑈ - MAR P 120° or 120" 121° 122° 123° 124° un or 125" 2 2" st Telse CELEBES SEA Subming CABLE Da. Persons CARLE - 1 Dame Л. Ameerang for 00 D. Polger :- I Abapt I Memerial Resendang - - Solos ( - - Twong Monetong Titamis Perio - Limbo Boy DECLASSIFIED times Belong GOLF VAN TOMINI MOLUKSCHE By Authority of JCS letter 7. 25-75 By SR Da L 3 19 o OF 0° GORONTALO - a 120° 121" 122" 123° 124° 125" NO. 3280 COMPILED AND DRAWN IN THE BRANCH OF RESEARCH AND ANALYSIS, 055 LITHOGRAPHED IN THE REPRODUCTION BRANCH, oss 19 APRIL 1944 FIGURE 1.3. Northern Celeber-Communications, FIGU JAN HALMAHERA CART TRACK Motorable . RADIO receiver anly for weather) BRIDLE PATH Some - WIRELESS able) FOOTPATH TELEGRAPH - ELECTRIC POWER PLANT PRACE MOROTAI a - A a E H A M - A Bene = Charges 2 N KAGE BANK . A sow - - 2 H WEDA BAAI $ K U By B SR Date JUL 31 1975 3 o M BATJAN - CRUMS La FIGURE 1 - 4. Halmabera-Communications. BRIEF Page I 27 copra and small amounts of coffee and rubber from northern fishing. About 70% of the population were classified as Christ- Celebes; copra and hemp from the Sulus; and copra and spices ians in 1935. from Halmahera, Sangihe, and Talaud. The Sangihe and Talaud Islands form a division under the Residency of Manado, which is in turn under the Government H. Finance. of the Great East. Barter is a common form of trade throughout the area. The C. Mindanso sector and Sulu Archipelago. (FIGURE I 6) Japanese have introduced scrip, using the names of the pre-war currencies of the occupied territories, and have tried to enforce There are at least 20 different ethnic groups in the Mindanao- its use for all transaction. The people, however, are probably Sulu area, of which 13 are pagan, 6 Mohammedan, and 1 Christ- hoarding the pre-war Philippine pesos and Netherlands Indies ian. The groups are chiefly Indonesian and Malayan; a few are guilders. Negritos or are intermixed with Megritos. The pagan groups show little cultural or political unity; the Moros, on the other hand, have many close cultural bonds stemming from their re- ligion, although they lack a national consciousness. The Chris- 17. People and Government tian Visayas form part of the general Visaya group of the cen- tral Philippines, which is the largest and most powerful cul- A. Halmahera sector. (FIGURE 1.5) tural and political group in the Islands. Most of the natives near the coasts have had contact with Portugal, the first European power to control the Moluccas, foreigners, and many of them have been employed as ordinary was driven out of Tidore in 1605 by the Dutch, who obtained a laborers on plantations. The Bagobos, Bilaans, Bukidnons, La- monopoly for the entire spice trade. In recent years, the great naos, Samals, Subanos, Sulus, and Visayas are all potential prosperity of Halmahera diminished with the decline of the sources of labor; the Visayas on the north and east coasts will spice trade. probably furnish the best laborers. Many workers are indifferent The natives of northern Halmahera, Morotai, Ternate, Ti- and unreliable, while the religious beliefs of the Moros some- dore, and Makian Islands are all of substantially identical stock; times interfere with their doing certain types of work or work- they are Alfoer tribes, the result of a mixture of Malays and ing at set hours. Consultation with the headman of a tribe, the Papua-Melanesians. The natives of southern Halmahera and of town mayor, or members of municipal governments should the Batjan group resemble the Papuans of New Guinea. The serve to provide sufficient labor. population of Halmahera is about 56,000; that of the off-lying The large Japanese population around the city of Davao, in islands is about 47,000. The northern Halmaherans speak at Davao province, which the Japanese now claim to total 30,000, least 13 mutually unintelligible languages of non-Malayan was strongly disliked by the natives of Davao, who massacred stock; the 7 or more languages spoken throughout the rest of the many groups of settlers. island are of Malayan stock. Ternatean is used as a lingua franca. The 10 provinces of Mindanao are classed as regular (Misa- Malay is known only in the harbor towns of Halmahera, but is mis Occidental, Misamis Oriental, and Surigao) and "special" fairly widespread throughout the off-lying islands. (Agusan, Bukidnon, Cotabato, Davao, Lanao, Sulu, and Zam- Most of the Halmaherans are pagan, but Christianity and boanga). "Special" provinces are much more subject to the Mohammedanism have made some advances in the coastal re- close and direct scrutiny of the central government than the gions. Mohammedanism is predominant in most of the off-lying regular provinces, and less entitled to the suffrage and to the islands, except in Morotai, where the pagans are by far the larg- election of their own officers. The ultimate aim is to transform est group. all provinces into regular provinces. The Secretary of the In- The natives of this sector are inclined to be surly, irritable, terior in the Philippine Cabinet is responsible for the supervi- and lazy. All villages can supply male carriers; some expert sion of all provincial and local governments in the Philippines. boatbuilders are available in the coastal areas. Internal dissension in Mindanao and Sulu has stemmed large- Administration of Halmahera and the off-lying islands was ly from the fact that the Filipino groups, chief of which are the vested in the Assistant Resident at Ternate, who was responsible Visaya and Tagalogs, have held most of the important official to the Resident of the Moluccas at Amboina, and ultimately to posts in the government, to the exclusion of the Moros. The the Governor of the Great East at Makassar. The territory of Moros lack sufficient education to be able to play an important the North Moluccas was divided into 2 areas, 1 under the part in the government, and suffer from profound splits within direct rule of the Netherlands Government, and the other under their own groups. the nominal rule of the Sultans, who coöperated with the Netherlands Government. Controleurs and Gezaghebbers were D. Northeast Borneo. (FIGURE I 5) administrative officers of subdivisions in the territories under direct rule. The natives' attitude toward both the Durch and The Dutch and English established footholds in Borneo in the Japanese is probably passive, although the old nobility of Ter- seventeenth century, and extended their influence in the course of the eighteenth century. Borneo remains one of the least de- nate may resent Dutch usurpation of their power. veloped parts of the East Indies. The inhabitants fall into 3 main groups: the Klamantan, in British North Borneo; the Bahau, B. Sangihe-Talaud sector. (FIGURE I-5) in central and east Dutch Borneo; and the Punan, in the moun- The natives of Sangihe resemble those of Minahasa in Cele- tains and deep forest of central Borneo. Of the 530,000 people bes; the Talauders show some physical differences. The people in Northeastern Borneo, about 84% (450,000) are natives, of the islands, which are overcrowded, are timid and inoffensive, 11% Chinese, and 5% other Asiatics and Europeans. and reluctant to serve as hired labor. They live by agriculture and The business language in the coastal towns is Malay, which is Page I 28 BRIEF also the chief language taught in schools. The tribes continue and yellow fever are widely distributed in the territories border- to speak their own tongues. ing on the Celebes Sea. Consequently, malaria is the principal The majority of the natives are pagan. The most important health problem and the first of the diseases of special military Christian missionary work has been the establishment of schools. importance. The disease is extremely prevalent throughout It has been necessary to import Chinese and Javanese laborers Halmahera, Sangihe, and Talaud, but no details are available. for work on rubber and tobacco plantations; of the 15,500 la- Malaria in the Philippines is a disease of the foothills and is borers in 1939, 7,000 were natives, 6,000 Chinese, and 2,300 transmitted neither in the coastal plains nor in the mountains. Javanese. Natives were employed as unskilled laborers on rub- Efforts have been made in Mindanao and Sulu to control the ber estates, oil fields, and at cutting timber. Other natives were disease, but since the malarial mosquitoes here are stream breed- engaged in small-scale agriculture. The Dusun are considered ers, oiling has proved ineffective. Malaria control in Borneo and good workers, although not so steady or reliable as the Chinese. Celebes has been simplified somewhat by the fact that the vec- About 30,000 males were available in the South and East Divi- tors are ground breeders and do not deposit their larvae in sions residency in 1939. The natives stay close to tribal centers plants, coconut shells, or small artificial containers. Blackwater and are unwilling to remain away from their homes for more fever occurs in Mindanao and Sulu but is known to be rare. The than 6 months at a time. next important diseases are typhoid fever and other intestinal British North Borneo was administered by the British North diseases. Bacillary and amebic dysentery are common in Halma- Borneo Company. A Governor of the island acted under the hera, as well as in North Borneo, Dutch Borneo, and Celebes. authority of a Court of Directors in London, assisted by a Gov- Acute outbreaks of amebiasis were reported from Tobelo and ernment Secretary and a Civil Service staff of 60 men. Dutch from Djailolo at the end of 1937. Dysentery is said to be com- Borneo was one of the Outer Territories in the Netherlands East mon on Sangihe and Talaud. Typhoid fever is prevalent through- Indies governmental organization. Three of the 8 subdivisions out the Philippine Islands, but few cases are reported from North included in this study were native-ruled, although the capital of Borneo. In Dutch Borneo and Celebes the disease is definitely each subdivision was ruled directly by the Dutch. The Japanese common. This is largely due to inadequacies in the drinking wa- have tended to retain the old boundaries. Natives courts coexist ter supplies and sewage systems. Paratyphoid fever and many va- with British and Dutch courts in Borneo. rieties of salmonella infections have been reported from many areas in the Netherlands Indies. Bacillary dysentery is by far the E. Northern Celebes sector. (FIGURE 1-5) most important enteric infection in the Philippines. It is said that A confederation of the 4 largest tribes of the northeastern the cases are largely sporadic but unsafe water and food supplies peninsula of Celebes, the Tombulus, Tonseas, Tontemboans, and augment the possibility of outbreaks. Amebic dysenteries occur Tondanos, was created in the seventeenth century for mutual much less frequently but cause much illness. The third group of protection. The Minahasans requested Durch aid against the disease of special military importance are the venereal diseases. Spanish in 1679, and have ever since remained friendly toward Only in Halmahera are syphilis and gonorrhea infrequent. In the Netherlands. the Philippines, gonorrhea is the most prevalent venereal disease The entire sector is inhabited by peoples of mixed ancestry. and will prove to be a serious problem for military forces there. The Minahasans, the largest group, are distinct from the other In Borneo gonorrhea rates as high as 80% have been reported tribes, and are said to have a strain of Javanese and a fair amount in some areas. Syphilis is fairly new but is spreading rapidly. of European blood. The total number of inhabitants in the area Occasional cases of chancroid and granuloma inquinale are en- is believed to be under 700,000. The coasts are fairly well popu- countered. In cities the rates are higher than in rural areas. lated; there are relatively few interior villages. Rickettsial diseases constitute the fourth group, though little Malay is generally comprehensible throughout the Celebes information is available on its occurrence in any sector. The sector. Natives who have attended high school know some only definite knowledge is that flea-borne murine typhus and Dutch, and a few probably know English. tick-borne scrub typhus do occur in the Philippines. Although Christianity is the most important religion in Minahasa, there are no specific data or scrub typhus in the area, its presence where 266,000 of 292,000 natives were Christians in 1935. should be strongly suspected. The current army typhus vaccine There were less than 5,000 Mohammedans. A very small num- does not protect against it. Another disease, dengue, occurs ber are pagan. abundantly in all parts of the area. It produces a low mortality The best laborers in the area are the Boeginese and South rate but a high non-effective rate and readily disables an entire Makassarese. They are usually obtained at Makassar. Many army. Also, the respiratory infections are an important source of Minahasan boys become clerks or join the army. trouble throughout the islands. Influenza, bronchitis, broncho- Northern Celebes falls within the Territory of the Great pneumonia, and lobar pneumonia are all quite prominent. Lobar East, whose capital is at Makassar. Manado Residency is one of pneumonia is one of the most frequent causes of death in the 6 within the Territory; the Residency contains 5 divisions and Netherlands Indies. Careful hygienic measures have not been 12 subdivisions. A large part of the Residency is under indirect rule of the Netherlands Government. The sector probably con- able to stamp out the dangers of pneumonia on the large plan- tains many pro-Japanese, as well as pro-Dutch, natives. tations. In this area, as in other tropical countries, skin diseases are a major affliction. Scabies, Dhobie itch, and common fungus in- 18. Health and Sanitation fections are prevalent. Impetigo is often seen in Halmahera. Tinea albigena is frequent and is localized in the palms and on A. Diseases. the soles. Epidermophytoris occurs and is highly communicable. Mosquitoes capable of transmitting malaria, filariasis, dengue, Prickly heat often bothers newcomers more than natives. Red FIGURE I 5 JANIS 155 BORNEO, CELEBES AND HALMAHERA POPULATION DENSITY 1930 o 50 100 150 200 250 BOUNDARIES DENSITY OF NATIVE POPULATION DENSITY OF EUROPEAN POPULATION MILES BY SUBDIVISIONS 0 50 100 150 200 250 KILOMETERS INTERNATIONAL (Number of persons per square kilometer) 1-10 PERSONS RESIDENCY 45-50 : LESS THAN 2 20-50 DIVISION 95-100 - SOURCE: VOLKSTELLUNG, 1930, VOLUMES 5 AND 6 SUBDIVISION 495-500 " 2-5 50-100 OVER 1000 (MANADO, 1392 PERSONS) 5-10 100-200 114° 116" 118" 10-20 Total population of Brit- 120° 122" 134° 126" 128° ish North Bornes in 1939, SANDAKAN 304,433. MINDANAO ADMINISTRATIVE DIVISIONS 6' AND Sggdaken D SULU ARCHIPELAGO BORNEO 40 - a SUBDIVISIONS KUDAT NO/RTH 1. Tidoengsche-Landen SANGIHE 0 TALAUD EILANDEN 2. Bowlowngon BORNEO, 3. Apokejon 4. Berson INTERIOR 5. Boven-Mahakam IMBLINE TALAUD-EILANDEN 6. West-Koatol 7. Oost-Koetal = 8. Poeroektjoce o CELEBES SEA SARAWAK MANADO RESIDENCY-CELEBES SUBDIVISIONS Tarekan E 9. Donggola SANGIHE-EILANDEN 10. Talbal 11. Boeol 19 1 12. Parigi 13. locieno 2 14. Gerentala 2" 15. Boloing Mangondow 16. Amoerong 17. Tondono CELEBES 18 18. Monado Manado C 19. Songlhe Ell. 5 20. Teloud BL 17 B R N STRAIT + Termite TERNATE DIVISION-HALMAHERA is 23 12 12 SUBDIVISIONS Gerentale MAKASSAR HALMAHERA 21. Djailelo 4 22. Tobelo 0' 23. Termite 24. Wede DOESOEN 900 25. Butjon 25 Donggolo LANDEN 114' 118" 120" 123" 124° 125" 128" COMPLED AND DRAWN a THE BRANCH OF RESEARCH AND ANALYSIS DSS JUNO LITHOGRAPHED - THE REPRODUCTION MANDL ons APRIL 1944 FIGURE 1.5. Borneo, Calebes and Halmabera-Population Density. FIGURE 1-6 JANIS 155 124° DENSITY OF NATIVE POPULATION BY PROVINCES, 1939 EYTE MINDANAO AND SULU Orgians / SOUND 10° Number of persons per square kilometer. SIARGAD 100-119 40-59 Under 20 Surigao 80-99 20-39 BUCAS GRANDE 0 29 N 100 NEGROS SIQUIDA : CAMIGUR Milles o 25 X 100 Butuan NORTH ISUIT Kiometers MINDANAO SEA OR SOUTH BLET MISAMIS LIANGA BAY A G U S A N Oroquieta Cagayan (LIGAN BAY SULU SEA G MISAMIS BUKIONON % Malaybalay Dansalan . M N D A N A 0 L N A o SAN MICUIL a D A y A o SIBUGUEY ILLANA BAY BAY BONGO OLUTANGA -8 Cotabato 0 Davad # CAGATAN BULU - a Zamboangs / MORO GULF BASILAN STRAIT C o T A . A T o DAVAO MAMBAHERAUMAN / BASILAN I - GULF :- 9 CABUCAN 8 TONSQUIL / JOLO LAPARAN DAMMAI PATALL LUGUE :- SAMALES X / BARANGAN - 6 CELEBES SEA BORNEO 1" B nines SIMUNIE = DARVEL BAY SIBUTU TAWITAMI / 119° 1 100° 123" 124" 129° 136° un 120° COMPILED AND DRAWN . THE BRANCH of RESEARCH AND ANALYSIS oss LITHOGRAPHED - THE REPRODUCTION BRANCH, on 3175 APRIL 1944 FIGURE 1.6 Density of Native Population by Provinces. BRIEF Page I 29 bug dermititis if often an intolerable annoyance. Cutaneous part of the curative medical work was undertaken by mission myiasis is common. hospitals and industrial hospitals in cooperation with the There are other diseases which might become military prob- Bureau of Health. The Bureau maintained 4 travelling X-ray lems though they have not been encountered in the area. In re- units for use in tuberculosis control work. A Malaria Control cent years there have been no cases of cholera or plague reported. Field Laboratory had headquarters in Bulacon Province, Luzon, Yellow fever has never occurred in any of this territory, although and Malaria Control units were located in the provinces of La- the vector of the disease, aedes aegypti, is found throughout. guna, Pangasinan, and Isabela with subunits in other provinces. There are other diseases, not of particular military importance The medical facilities and the public health program of North but likely to affect small numbers of troops. The first of these Borneo were inadequate. This was due in part to limited funds is tuberculosis which is prevalent in the area in all forms, and and personnel, to the difficulties of transportation, and to the ranks as the single greatest cause of death. It is not believed that ignorance of the natives. A small amount of malaria control had this disease will be of great military significance for well selected been carried out at Jesselton, Tawau, Sandakan, Tenom, and white personnel. Also, worm infections are extremely common Keningau. The work undertaken by the Dutch Government in throughout the Philippines, ascariasis and trichuriasia being the the Netherlands Indies has led to important results in many most prevalent forms. Hookworm disease is endemic. The com- fields. This is surprising since the number of physicians is very bination of hookworm and malaria is dreaded especially because small. The small body of medical pioneers was able to improve of the resultant severe anemia. Filariasis has been observed in sanitary conditions to a point where life offered few special the Philippine Islands, North Borneo, Sangihe and Talaud, and health dangers for foreigners. Halmahera. Schistosomiasis due to Schistosoma japonicum OC- curs in Northern Mindanao. Yaws is prevalent throughout the E. Hospitals and medical personnel. area, though it is more common in lowland than in mountain At the end of 1938 there were 25 hospitals in Mindanao and districts. Eye diseases are also commonly prevalent in the area. It in Sulu Province, exclusive of United States military and naval is estimated that in Celebes alone there are at least 10,000 per- hospitals. In general the hospitals were fairly well equipped and sons who are blind or nearly so. The loss of vision is tue to trach- able to offer a variety of services. Public health laboratories oma, gonococcal ophthalmia, and syphilitic uveitis. Leprosy is were maintained in the provinces with their facilities available extremely common. Other miscellaneous diseases are smallpox, free of charge. In every instance the hospitals, laboratories, and diphtheria and tetanus, common in Borneo and Celebes, and clinics were utilized fully and increased capacity was a constant measles. Malnutrition and beriberi are common because of the need. Almost all medical supplies were imported. The only great poverty of the natives. medicinal product available locally was totaquinine, a new qui- nine preparation which was supposed to be very effective. In B. Water. North Borneo in 1939 there were 4 general hospitals under In general there is an adequate supply of water available in government direction. These were at Sandakan, Jesselton, Beau- all parts of this area except the eastern part of the Jolo Island fort, and Tawau. The medical department maintained a system group of the Sulu Archipelago when the supply is sometimes in- of dispensaries operated by native dressers which were scattered adequate. All water should be regarded as potentially dangerous throughout the rural areas. A special clinic for the treatment of and should be boiled or chlorinated before use. Containers venereal diseases was established at Sandakan. In 1940 there should be kept clean, and ice made from local water supplies was a total of 63 hospitals on the Celebes Islands, 28 in the should not be used for drinks. Government of Celebes, and 34 in the Government of Manado. The larger of these were fully equipped with X-ray apparatus, C. Sanitation. surgical instruments, and laboratory facilities. The 5 hospitals on Halmahera were poorly organized, poorly built, and inade- In most of the area, excreta are disposed of directly to a quately equipped. In some cases even the sanitary conditions stream, to the ocean, or to the soil. In parts of the Sulu Archi- were unsarisfactory. No information as to hospital facilities on pelago, houses are built on stilts and all waste materials are Sangihe and Talaud is available. dropped through holes to the ground below. In the Philippines There were 4,909 licensed physicians in the Philippines as of a campaign was carried out for the provision of bored hole la- 1 January 1940. About 90% of these physicians were Filipinos, trines and in 1937 it was estimated that there was 1 such latrine and a great majority were graduates of the 4 local medical col- for every 8 persons. No reliance should be placed on the avail- leges. No reports are available for North Borneo after 1937, ability of any sewage disposal facilities. Because of the preva- but at that time the medical staff consisted of 6 European medi- lence of enteric diseases, special attention must be paid to the cal officers, and an auxiliary staff of nurses, midwives, and male careful disposal of sewage by approved methods in order to safe- dressers. In Celebes there were 41 physicians; in Halmahera 3 guard against pollution of water and soil and access by flies. public health physicians and Indonesian nurses. D. Public health. F. Food. It is impossible to consider the public health organization of In general, the natives in this area are fairly well nourished, the entire area, since each sector is only a small part of a larger although they also suffer from the effects of inadequate nutri- organization. The Philippine Government has made many ef- tion, due either to poverty or to ignorance. The native diet is forts to improve health conditions and its success has been re- made up of fish, rice, leafy vegetables, and fruit. As a general markable. At the end of 1938 there were 16 government hos- rule, Americans and Europeans used imported foods, since lo- pitals on Mindanao and the Sulu Archipelago and 2 semi-gov- cally grown vegetables must be considered unsafe when cooked. ernment hospitals supervised by the Bureau of Health. A large In the Netherlands Indies there are some chickens, but they lay Page I 30 BRIEF very small eggs. Ducks are available in large numbers. There is B. Organization. little surplus milk and in every instance it should be boiled be- (1) Administration. fore consumption. Local cattle are often tubercular, and meat The Celebes Sea Area is under the Southwest Area Fleet with should be carefully inspected if it is used. The food supplies headquarters at Singapore. This fleet is subdivided into 4 South- should, as a general rule, be imported entirely. ern Expeditionary Fleets each covering a defined area within the Philippines-Indies-Malays region. The Thirteenth Air G. Insects and animals. Fleet is the Naval Air Arm of the Southwest Area Fleet. Mosquitoes capable of transmitting malaria, filariasis, den- Sector E, Northeast Borneo as defined in this study, is under gue, and yellow fever are widely distributed throughout the ter- the jurisdiction of the Twenty-second Base Force with head- ritories surrounding the Celebes Sea. The 3 main species present quarters at Balikpapan, which is a subdivision of the Second are the Anopheles, Aedes, and Culex. Lice are common, particu- Southern Expeditionary Force. The Third Southern Expedition- larly in Borneo, Celebes, and Halmahera. Flies are found in ary Force, covering the Philippines, is based at Manila. Under it, large numbers and act as vectors of enteric diseases. Sandflies, the Thirty-second Base Force, with headquarters at Davao, has ticks, and mites are present, though they do not act as vectors. jurisdiction over sectors C and D, Mindanao, and the Sulu Archi- The oriental rat flea is the principal vector of plague and is pelago, respectively. The recently organized Fourth Southern present throughout the area. Rats are númerous and act as a Expeditionary Fleet has as 1 of its subdivisions the Twenty- reservoir of plague. Poisonous spiders must be guarded against sixth Base Force with headquarters at Kaoe. The Twenty-sixth constantly. The spectacled cobra, the king cobra, and the Philip- Base Force has jurisdiction over Sector A, Halmahera, Sector B, pine cobra are found in Mindanao and Sulu. The king cobra may Sangihe-Talaud Islands, and Sector F, Northern Celebes. be found in dense jungles near streams and sometimes in trees. It is believed that administrative control of the Japanese The spectacled cobra is the most deadly, and frequently enters Army Air Service emanates from Manila, Specific details are houses in search of rats on which it feeds. Kraits are common not available. throughout the Philippines. Other poisonous snakes are found (2) Tactical. but they seldom attack man. On Halmahera poisonous snakes are rare. Crocodiles are found throughout the area and jungle The Japanese Army Air Service is responsible for support of animals are found on Borneo. Some fish are poisonous and ground forces, bombing of forward allied bases, and local air should not be eaten. Pests are everywhere present and will be defense. Its employment is controlled by the senior Japanese great nuisances if men aren't supplied with protective clothing. field commander in the area. At present in the Philippines and Netherlands East Indies, excluding Sumatra, the Fourth Air Army is estimated to be exercising command over probably 2 air divisions, 2 air brigades, approximately 5 air regiments, and 19. Naval and Air Facilities possibly 5 independent air squadrons. The Naval Air Service executes long range reconnaissance, The Celebes Sea Area is one of the most important Japanese submarine patrol, shipping escort, attacks on Allied surface defense zones. Loss of the area would make Japanese shipping vessels, and local air defense under direction of the senior fleet lanes south and southwest of Hong Kong and Formosa vulner- commander in the area. It is believed that the Thirteenth Air able to Allied sea and air attacks and would cut off sources of Fleet now commands 1 air flotilla and approximately 7 or 8 air material essential to the Japanese conduct of the war. The num- groups in the Philippines and Netherlands East Indies exclud- erous airfields on the islands bordering the Celebes Sea Area are ing Sumatra. vital to its defense and are important in strategic plans for de- (3) Disposition of forces. fense of Greater East Asia. A concentrated effort to strengthen The normal strength of the naval base forces in the area is and further develop both naval and air installations in the area weak. Small naval garrisons are stationed at shore installations may be expected. and sea forces include only a few patrol and mine craft and miscellaneous small coastal vessels. It is difficult to arrive at A. History and development. figures on naval air strength owing to the mobility of the Jap- The Japanese advance into Netherlands East Indies early in anese air forces and the continuing development of air facili- 1942 proceeded so rapidly that no particular effort was made to ties. Estimates for the Philippines and Netherlands East Indies develop naval facilities in Northeast Borneo, Northern Celebes, excluding Sumatra, for the first quarter of 1944, fluctuated be- tween a high of 498 and a low of 270 aircraft. Mindanao, and Halmahera. Capture of the Singapore and Soura- baya naval bases in February and March of 1942 fulfilled Jap- C. Supply and maintenance. anese needs for advanced naval bases and the development of (1) Depots. other installations was confined to the most forward areas. Principal naval supply depots for fuel, munitions, and ma- Until allied progress in New Guinea, in the Solomon Islands, teriel in general are at Davao and Kaoe. Only minor repair fa- and in the Marshalls coupled with increasing attacks on the Caro- cilities are available throughout the area. No information is lines and Mariannas, became a serious threat, the Japanese main- available on the location of aircraft supply and maintenance tained only very small forces in the Celebes Sea area. Since depots. January, 1944, constructive activity in connection with both (2) Supply routes. naval and air facilities has become intensive various points Principal supply routes to and within the area are shown on in the area. the accompanying map. (FIGURE XII 1) BRIEF Page I 31 The air ferry route from Japan leads southwest by way of Polloc Harbor, and Davao Gulf on Mindanao Island; West Formosa and the northern Philippines to Del Monte and Davao Tawitawi Bay and Tutu Bay in the Sulu Archipelago. on Mindanao Island, thence to Menado on Celebes Island and from there to delivery points in the Netherlands Indies. E. Air facilities. D. Naval facilities. The Celebes Sea Area as a whole is eminently suited to sea- Within the Celebes Sea area there are no naval bases or sta- plane operations. Most of the islands in and surrounding it are tions which may be properly so-called. Kaoe and Davao are suitable for construction of airfields and landing grounds and headquarters of Japanese base forces but facilities at those points many such facilities have been developed, formerly by commer- are limited. Several bays and harbors are regarded as potential cial airline companies and, since the occupation, by the Japan- naval bases possible of extensive development. These include ese. The following tables list seaplane facilities, airfields, land- the Wasile-Kaoe Bay on Halmahera Island; Dumanquilas Bay, ing grounds, and possible airfield sites in the area. TABLE I 4 SEAPLANE FACILITIES Sector A: Halmabera NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 1. Ternate 0° 46' N, S.A.A. Just east of Ternate 1. off west Unlimited runs north to Fair shelter and anchorage; 4 127° 23' E coast of Halmahera. south and northeast to mooring buoys and a slipway re- southwest. ported; dispersal for 20 aircraft; other facilities. 2. Berri Berri 2° 23' N, E.S.A.A. Off northeast coast of Morotai I. No data. Sheltered by reefs and Tabailengi 128° 40' E Island. 3. Bobane Bay 0° 52° N, E.S.A.A. At the head of Kaoe Bay. No data. Sheltered anchorage for several 127° 41' E seaplanes. 4. Bori Island 0° 35' N, E.S.A.A. Between a small island and the No data. Reported as a good concealment 127° 36' E mainland of Batjan Island. area. 5. Galela Lake 1° 49' N, E.S.A.A. Near town of Galela on north- No data. Invisible from sea. Best anchorage 127° 49' E ern peninsula of Halmahera Is- on east side of lake. Use of buoys land. is advised. 6. Groot Geelmulden E.S.A.A. Across Obi Strait, 351/2 miles No data. Anchorage at north end of aroll. Atoll 1° 04' S, northeast of Obi Major. 128° 15' E 7. Labohea 0° 39' N. E.S.A.A. In Awanggo Bay, at head of La- No data. No details. 127° 28' E boeha Bay, just southwest of the town. 8. Lebessan Island E.S.A.A. In a small bay off the east coast No data. No details. 3° 29' N. of Sangihe Island, 128 miles 125° 39' E north-northeast of the northeast tip of Celebes Island. 9. Moeilijk 0° 34' N, E.S.A.A. Atoll, 15 miles east of Halma- No data. A hiding place on west side of 128° 22' E hera Island. Moeilijk Atoll. 10. Sololo Bay 0° 48' N, E.S.A.A. At head of Boeli Bay. No data. Reported hiding place. 128° 13' E 11. Tahoena 3° 36' N, E.S.A.A. Off west coast of Sangibe Is- No data. Open to northwest monsoon. Pier 125° 29' E land. and radio station available. 12. Talawide 2° 41' N, E.S.A.A. Reported in a lake on Siace Is- No data. No details. 125° 24' E land at center of Sangibe Islands. Page I 32 BRIEF TABLE 1. 4 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 13. Tifore Island E.S.A.A. In Laboehan Bay on east coast of No data. Maneuvering in bay not possible. 0° 58' N, Tifore Island. Planes can be beached. 126° 09' E 14. Tobelo 1° 44' N, E.S.A.A. Just north-northeast of Tobelo; No data. Two landing stages. Planes can be 128° 01' E berween Tobelo Island and Hal- beached. mahera Island. 15. Wasile Bay E.S.A.A. In northern part of Kaoe Bay, No data. Mooring area adjacent to north or 1° 12' N, on northeast peninsula of Hal- south shore according to prevail- 128° 08' E mahera Island. ing monsoon. 16. Weda Bay 0° 19' N, E.S.A.A. Just south of Weda at head of No data. No details. 127° 52' E Weda Bay. Sector C: Mindanao 17. Malalag Bay 6° 36' N, S.A.A. In southwest part of Davao Gulf, Four miles long, north- Bolton reef at middle of entrance 125° 25' E. 2 miles north of Baculing Hills, west to southeast; 11/2 to bay an obstruction; depths 6 to 58 miles northwest of Cape miles wide. 30 feet; mooring for 4 PBYs; sev- Agustin. eral sandy beaches suitable for hauling out. 18. Zamboanga Harbor S.A.A. Just south of town of Zamboan- No data. Sheltered from northeast mon- 6° 54' N, 8ª at southwest tip of Mindanao soons; depths 6 to 30 feet; good 122° 05' E Island. anchorage near wharf in 28 feet; minor repairs and accommodations at Zamboanga. 19. Bugo 8° 30' N, E.S.A.A. In Macajalar Bay. No data. Small craft available. 124° 45' E 20. Davao Gulf E.S.A.A. In Davao Gulf, 4 miles east of Runs of 5% miles in any Limited shelter; minor repairs and 7° 06' N, Samal Island. direction. fuel. 125° 39' E 21. Dapitan Bay E.S.A.A. West of Dapitan town in the Runs of 21/4 miles in any No details. 8° 39' N, bay off north end of west penin- direction. 123° 24' E sula of Mindanao Island. 22. Hinatuan Bay E.S.A.A. In the bay west of Hinatuan Two and one-half miles No other details. 8° 21' N, Village on west side of Minda- east to west; 11/2 miles 126° 21' E não Island. north to south. 23. Igat Bay 7° 35' N, E.S.A.A. On south side of west peninsula Three miles north to south; No details. 123° 10' E of Mindanao; on east arm of 3 miles east to west. Dumanquilas Bay. 24. Isabela 6° 42' N, E.S.A.A. In Isabela Channel between Ma- No data. No details. 121° 58' E lamaui and Basilan Islands. 25. Lake Buluan E.S.A.A. About 38 miles west of Davao No data. No details. 6° 41' N, Gulf and 45 miles north of Sa- 124° 48' E rangani Bay. 26. Lake Lanao E.S.A.A. Near the center of Mindanao Is- Runs of over 5 miles in No other details. 7° 59' N, land. any direction. 124° 21' E 27. Masinloc Anchorage E.S.A.A. In the channel berween Sacol Run of 3 miles northeast No other 6° 55' N, details. and Mindanao Islands. to southwest. 122° 10" E 28. Murcielagos Bay E.S.A.A. In Casul Bay, the south arm of Runs 12,000 feet north to No other 8° 35° N, details. Murcielagos Bay, off the north south; 8,000 feet north- 123° 34' E tip of the west peninsula of Min- northease to south-south- danao. west. 29. Nasipit Harbor E.S.A.A. In Nasipit Harbor west and One mile north to south; No other 8° 59' N, details. southwest of Nasipit town, 10 3,000 feet northeast to 125° 20' E miles southeast of Diuata Point. southwest. 30. Polloc Harbor E.S.A.A. On the west side of Mindanao 7° 22' N, Two miles north to south, No other details. Island, just west of Parang. 3 miles ease to west. 124° 14' E BRIEF Page I 33 TABLE I 4 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 31. Port Banga E.S.A.A. On east side of the southwest 7° 32' N, Three miles northeast to No other details. peninsula of Mindanao Island; southwest. 122° 27' E separated from Sibuguey Bay by Linguisan Point. 32. Port Holland E.S.A.A. Just northeast of Port Holland 6° 33' N, Long runs available. No other details. in Malusu Bay, 4 miles south- 121° 52' E east of Pangasahan Hill, 929 feet elevation. 33. Port Lamon E.S.A.A. West of the wharf on north side Two miles east to west. No other details. 8° 28' N, of the bay. 126° 23' E 34. Port Lebak E.S.A.A. In Port Lebuk on southwest part Over 1 mile east to west No other details. 6° 32' N, of Mindanao Island. and north to south. 124° 03' E 35. Port Misamis E.S.A.A. In Port Misamis on north cen- No data. No details. 8° 08' N, tral part of Mindanao, 12 miles 123° 50' E southeast of Mount Malindang, elevation 8,950 feet. 36. Port Santa Maria E.S.A.A. On west coast of Zamboanga No data. No details. 7° 46' N, Peninsula, northeast of Mount 122° 06' E Santa Maria, elevation 646 feet. 37. Port Sibulan E.S.A.A. In Tantalang Bay at the head of Three miles cast to west No other details. 7° 31' N, Port Sibulan, east of Naga Naga, and north to south. 122° 55' E on south side of the west penin- sula of Mindanao Island. 38. Taba Bay 7° 32' N. E.S.A.A. In Taba Bay north of Lumaro, One mile northeast to No details. 122° 49' E about 2 miles southwest of southwest; 21/2 miles north- Mount Sibuguey, elevation 1,050 west to southeast. feet. Sector D: Sulu Archipelago 39. Banaran Island E.S.A.A. Off northeast side of island No data. Good shelter from nearly all 5° 01' N, which is in Tawitawi group. weather. 120° 08' E 40. Baru Batu Bay E.S.A.A. Off the south coast of Tawitawi No data. No details. 5° 04' N, Island on east side of bay at New 119° 53° E Batu Batu. 41. Capual Channel E.S.A.A. In Capual Channel north of Three miles east-southeast Open to the southwest. 6° 01' N, Liangliang on Jolo Island. to west-northwest. 121° 24' E 42. Jolo Harbor E.S.A.A. Near the wharf in Jolo Harbor Three thousand feet in all Facilities for minor repairs. 6° 04' N, on the northwest coast of Jolo directions. 121° 00' E Island. 43. Luuk Sula Bay E.S.A.A. At the head of Luuk Sula Bay One mile east to west and No other details. 5° 03' N, on south coast of Tawitawi Is- I mile east-northeast to 119° 52' E land, about 1 mile north of Pa- west-southwest. tong Point. 44. Maraning Bay E.S.A.A. Off northwest coast of Tawitawi No data. No details. 5° 15' N, Island, 314 miles southwest of 120° 02' E Languyan Point. 45. Port Bongao E.S.A.A. North of Bongao Island, south of One mile east-northeast to Run could extend 2 miles into 5° 02' N, Sanga Sanga Island, west of Pa- west-southwest. Chongos Bay. Radio station at 119° 46' E pahag Island. Bongao. 46. Port Languyan E.S.A.A. In Port Languyan on the cen- No data. Reported an excellent alighting 5° 16' N, tral northwest coast of Tawi- area; bordered by a mangrove 120° 04' E tawi Island. swamp, with some beach frontage. 47. Siburu Island E.S.A.A. In the north lagoon of the is- No data. Ample room for landings and take- 4° 48' N, land. offs reported. 119° 22' E Page I 34 BRIEF TABLE 1-4 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 48. Tataan Pass E.S.A.A. Berween Tataan Island and Ta- Two miles north to south, There are two reefs in the pass 5° 11' N, witawi Island. 3 miles northeast to south- about ½ mile offshore. 119° 55' E west. Sector E: Northeast Borneo 49. Abai River E.S.A.A. On the Abai River about 11/2 No data. No details. 6° 22" N, miles inland and about 5 miles 116° 21' E west-northwest of Kota Belud, on north side of east-west reach. 50. Ambong Bay E.S.A.A. Five miles southwest of the No data. Well-sheltered. 6° 19' N, Abai River on norchwest coast 116° 18' E of British North Borneo. 51. Balambangan Island E.S.A.A. In Lung Bay on east coast of is- No data. No details. 7° 17" N, land which is west of Banguey 117° 01' E Island. 52. Balung River E.S.A.A. Nineteen miles east of Tawao, Two reaches 114 miles by No details. 4° 18' N, 15 miles due west of Cowie Har- 600 feet lying east to west 118° 11' E bor. and north to south. 53. Boeaja 1° 26' N, E.S.A.A. Off the northeast coast of a large No data. No details. 118° 27' E headland on the east coast of Borneo. 54. Cowie Harbor E.S.A.A. In Coal Mine Reach, on east Area unlimited. Well-sheltered. 4° 15' N, coast of Borneo. 117° 50° E 55. Jesselton E.S.A.A. Between Gaya Island and Jessel- No data. Some repair facilities, a pier, and a 5° 59' N, ton Harbor on northwest coast crane. Occasionally used by both 116° 05' E of British North Borneo. civil and military aircraft prior to Japanese invasion. 56. Kinabatagen River E.S.A.A. Thirty-six miles east of Sandakan No data. No details. 5° 37" N, and 2½ miles souchwest of 118° 35° E Driftwood Point. 57. Kudar 6° 53' N, E.S.A.A. About 1/2 mile west of Kudat No data. Two mooring buoys. No evidence 116° 51' E wharf on west side of an inlet on of use by Japanese since occupation north end of the west arm of in January 1942. North Borneo. 58. Kalumpang River E.S.A.A. Thirty-two miles east of Tawau, No data. No details. 4° 20' N, I mile north of Kalumpang and 118° 21' E in the river east of Mangrove Island where the stream divides. 59. Labuan 5° 17' N, E.S.A.A. In Victoria Harbor on south- Approximately 6,000 feet 115° 15' E Two moorings, I pier. Fuel and oil east coast of Labuan Island. in all directions. storage facilities. RAF flying boats operated from here. No evidence of Japanese use or development. 60. Lahad Datu E.S.A.A. West of Jerry at Lahad Datu in No data. 5° 02' N, Good anchorage. Darvel Bay on southeast coast 118° 20' E of North Borneo. 61. Maruap River E.S.A.A. Northwest of Evans Island off 5° 25' N, Described as ample alight- No details. extreme northease coast of Bor- ing area, 118° 16' E neo. 62. Mitford Harbor E.S.A.A. Near south coast of Banggi Is- No data. 7° 08' N, No details. land off the north coase of Bor- 117° 07' E neo. Exact location unknown. 63. Papar 5° 45' N, E.S.A.A. In the lower reach of Papar Riv- No data. 115° 55' E No details. er, about 20 miles south-south- west of Jesselcon on the north- west coast of Borneo. Near the Jesselton-Linkungan Railroad, BRIEF Page I 35 TABLE 1.4 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 64. Sandakan E.S.A.A. In the harbor % mile west- No data. No moorings. Limited repair facili- 5° 49' N, southwest of the government ties. Slipway available but unsuit- 118° 07' E pier. able for large aircraft. Fuel and oil available but location of storage unknown. 65. Tarakan 3° 16' N, E.S.A.A. Off the southwest coast of Tara- No data. Sheltered. Gasoline and oil avail- 117° 36' E kan Island just east of the town. able. Facilities for minor repairs. 66. Timbu Nata E.S.A.A. Off the south coast of Timbu No data. No details. 4° 34' N, Mata Island just south of Darvel 118° 32' E Bay. Sector F: Northern Celebes 67. Amoerang Bay E.S.A.A. In southwest part of Amoerang Three and one-half miles No other details. 1° 12' N, Bay, just north of Amoerang on in any direction. 124° 34' E the northeast coast of Celebes Island. 68. Bangka Strait E.S.A.A. In southwest part of Bangka Reported unlimited. Well-sheltered. 1° 41' N, Strait, just north of Likoepang. 125° 03' E 69. Belang Harbor E.S.A.A. In Belang Harbor just northeast No data. Sheltered anchorage. 0° 57' N, of Belang. 124° 47' E 70. Dampelas Lake E.S.A.A. In Dampelas Lake on Dampelas No data. No details. 0° 11' N, Cape, southeast of Makassar 119° 52° E Strait, just southeast of Sabang village. 71. Danau Lake E.S.A.A. In southwest corner of Danau No data. Surrounded by mountains. 0° 46' N, Lake, just south of Kotamo- 124° 28' E bagoe. 72. Gorontalo Bay E.S.A.A. In Gorontalo Bay just south of No data. No details. 0° 28' N, Gorontalo on the south coast of 123° 03' E Menado Peninsula. 73. Kakas 1° 11' N, E.S.A.A. In the southwest corner of Lake No data. Fuel and oil available. Mooring 124° 53' E Tondano, 4 miles northease of buoys believed present. Langoan. 74. Koeandang Bay E.S.A.A. On the east side of Koeandang No data. No details. 0° 51' N, Bay on the north shore of Ma- 122° 54' E nado Residency. 75. Lembeh Strait E.S.A.A. In the south part of Lembeh Three miles northeast to No details. 1° 26' N, Strait between the northeast southwest and 1/4 to % 125° 11' E coast of Celebes and Lembeh Is- mile wide. land. 76. Limboto Lake E.S.A.A. On the south side of Limboto No data. No details. 0° 35' N, Lake on the south central part of 122° 58' E the north peninsula of Celebes Island. 77. Manado Bay E.S.A.A. In Manado Bay just north of No data. Four mooring buoys. Unprotected. 1° 30' N, Manado. 124° 50' E 78. Santigi Bay E.S.A.A. In Santigi Bay on north coast of No data. Alighting area is east to west. 1° 20' N, Celebes. 120° 55° E 79. Talise Island E.S.A.A. Reported at Talise Island, 10 No data. No details. 1° 52' N, miles north of north tip of Cele- 125° 05' E bes Island. 80. Tasoeka 1° 11' N, E.S.A.A. Also in southwest corner of No data. Fuel and oil available. Moorings 124° 54' E Lake Tondano. believed present. Page I 36 BRIEF TABLE I 4 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 81. Telok Pagalongian E.S.A.A. On the south side of Dondo Bay No data. No details. 0° 50° N, about 2 miles north of Boeloe- 120° 34' E tong. 82. Tolitoli Bay E.S.A.A. Just north of Kampoengbaroe No data. Small jetty, beaching facilities, 3 1° 03' N, town, northeast of Dondo Bay. mooring buoys, and a radio sta- 120° 48' E tion formerly available. 83. Tondano Lake E.S.A.A. On Tondano Lake which lies No data. Anchorages at Tasoeka, Kakas, and 1° 17' N, near the tip of Manado penin- Tondano. 124° 55' E sula. TABLE I 5 AIRFIELDS AND LANDING GROUNDS Sector A: Halmabera NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 1. Galela 1° 52' N, MAD On Galela Plain, 3% miles north- No. 1 runway, 4,500 by Extensive dispersal system. Capac- 127° 49' E west of Galela on northern penin- 250 feet northeast to ity, 158 bombers, 100 fighters. sula of Halmahera Island. southwest. No. 2 runway Field still under construction. 4,700 by 290 feet, north- Buildings nearby. Extensible east to southwese. 2. Lolobata 1° 17' N, MAD On the north coast of Lolobata Runway 4,600 by 500 feet Ample dispersal. Capacity, 34 128° 06' E Cape on west side of northeast north-northeast to south- bombers, 10 fighters. Field re- peninsula of Halmahera 1, 21/2 southwest. ported in excellent condition. miles northwest of Lolobata. 3. Miti 1° 34' N, MAD On the northwest side of Miti Is- Runway 4,600 by 350 feet Capacity, 95 bombers, 40 fighters. 128° 04' E land close off the east coast of the north to south. Thirty-five unprotected bomber dis- north peninsula of Halmahera Is- persal points. Reported serviceable land. in all weather. 4. Kaoe 1° 11' N, FLG One and one-half miles west of Runway No. 1, 4,500 feet Capacity, 50 bombers, 80 fighters. 127° 53' E Kaoe, just east of Kaoe River, on north to south; No. 2, Field tends to become water-log- the north coast of Kaoe Bay. 3,600 by 300 feer north to ged, landings possible only on run- south, 4,000 feet north- ways. Several buildings near run- east of No. 1. way. 5. Laboeha 0° 38' S, ELG Approximately 1 mile east-south- Length of runway, north- 127° 29' E Estimated capacity reported as 25 east of Laboeha on Batjan Island, east to southwest, un- bombers, 25 fighters. Site may of- west of the south end of the south known. fer possibilities of expansion and peninsula of Halmahera Island. further development. 6. Oba 0° 45' N, FLG Just east of Sofifi on west central Runway 3,400 feet north- 127° 34' E Estimated capacity, 10 bombers, 15 coast of Halmahera Island. west to southwest with no fighters. Ample room for construc- flight gaps. tion of dispersal facilities. Runway extensible to possibly 6,000 feet. 7. Pitoe (Doroeba) MLG Just east of Doroeba on southern- Approximately 5,000 feet 2° 03' N, Reported still under construction. most tip of Morotai Island, 10 northeast to southwest. 128° 18' E miles east of north end of the north- Dispersal for 5 bombers, 5 fighters observed. ern peninsula of Halmahera Island. Sector C: Mindanao 8. Davao 7° 07' N, FAD Six miles north of Davao, 7 miles 125° 39' E Runways 3,346 by 164 south of Bunawan on west side of North-south runway paved. Serv- feet north to south; 2,624 Davao-Bunawan highway. iceable in all-weather. One hangar feet northeast to south- reported. Ample area and cover for west. dispersal. 9. Davao-Cabaguio FAD Three miles north-northease of Da- Runway 2,850 feer north 7° 06' N, vao, on south side of the Davao to Ample cover for dispersal; 1 hang- to south. 125° 37' E Bunawan highway. ar. Strip 2,640 by 66 feet reported paved. 10. Alah River ELG Just south of Sapali Barrio on east 6° 16' N, Runway approximately bank of Alah River. Estimated ele- Good cover nearby. No other de- 1,250 by 125 feet, exten- 124° 44' E (approx.) tails. vation 1,200 feet. sible. BRIEF Page I 37 TABLE I , (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 11. Barobo 8° 32' N, FLG Four miles west of Barobo barrio; Runway 3,328 by 197 feet Field soft after rains but drainage 126° 05' E 7½ miles south of Lianga near east to west. good. Near road from Barobo to southwest shore of Lianga Bay. Tambis. Accommodations at Tam- bis Mining Company. 12. Bassa Point ELG Near Bassa Point on north tip of Approximately 2,000 by No details. 7° 10' N, Samal Island in Davao Gulf. 500 feet. 125° 44' E (approx.) 13. Bual 6° 04' N, ELG Two and one-half miles south of Estimated 750 by 50 feet. Some cover nearby. 125° 08' E (approx.) Makar River mouth near west No other details. shore of Sarangani Bay. 14. Buenavista (San MLG At Risal barrio 21/2 miles south of Reported 5,249 by 328 Field has clay surface with a central Jose de Buenavista) Buenavista on Butuan Bay; 10 feet north-northease to gravelled strip 2 inches thick and 8° 56' N, miles west of Butuan. south-southwest. 75 feet wide. Drainage poor. Soft 125° 23' E in wet weather. 15. Buluan 6° 42' N, HLG At east edge of town of Buluan just Reported 5,249 by 328 Field sodded, sandy loam, all-weath- 124° 47' E northwest of Lake Buluan. feet east to west. er. Cover available. Camouflage nets and pens built in 1942. Philip- pine Constabulary barracks nearby. 16. Buruan 8° 57' N, ELG On west edge of town of Buruan in North to south 1,950 by Surface is sodded clay loam. Possi- 125° 31' E Agusan Province near west bank of 195 feet. bly extensible. Ample cover. Ac- Agusan River. cess by road and waterway. Tele- phone and telegraph in town. 17. Buruan-Bancase FLG Three miles south of Butuan Bay at Reported 2,427 by 98 feet Reported paved. Access by road 8° 57' N, barrio of Bancase, 4 miles west of northwest to southeast. and waterway. Barracks at adjacent 125° 28' E Butuan. Philippine military reservation. 18. Cagayan 8° 29' N, MLG Two miles west of Cagayan on the Runways 4,265 by 328 Considered an all-weather field for 124° 38' E Cagayan to El Salvador highway, northwest to southeast, 3,- fighter aircraft. Abundant cover 21/2 miles south of Macajalar Bay. 609 by 328 feet north to nearby. Road transportation to south. dock at Cagayan. Buildings avail- able. 19. Corabato 7° 12' N, FLG At barrio of Kakar 2 miles south of Runway 2,625 by 164 feer Reported enlarged and in active 124° 14' E Cotabato. northwest to southeast. use. Sodded hard ground, slightly rolling. Reported all-weather. Am- ple cover nearby. Buildings avail- able. 20. Dadiangas 6° 08' N, ELG At barrio of Dadiangas berween Reported 1,969 by 164 Level and sandy, all-weather. Two 125° 10' E Silvay and Makar river mouths, 1 feet northwest to southeast. new runways, each 3,281 by 328 mile north of Sarangani Bay. feet, were under construction in 1941. 21. Davao-Ipil ELG Three miles northeast of Davao at Reported 1,626 by 189' Grass surface. Ample cover nearby. 7° 06' N, the south entrance to Pakiputan north to south. 125° 38' E Strait. 22. Del Monte No. 1 HLG Fifteen miles southeast of Cagayan, Reported 7,000 by 600 All-weather, suitable for all types 8° 21' N, on west bank near headquarters of feet northeast to southwest. of aircraft. Ample area for dis- 124° 49' E (approx.) second south triburary to Tagoloan Elevation estimated 1,500 persal but with little cover. River. feet. 23. Del Monte No. 2 FLG At Del Monte Club 2 miles west of Runways 3,300 by 300 Sodded hard ground. All-weather. 8° 20' N, Tankulan, 2 miles southwest of Del feet north to south, 2,200 Ample dispersal area with limited 124° 47' E Monte No. 1. Eleveation 1,200 feet. by 300 feet east to west. cover. 24. Del Monte No. 3 HLG One-half mile west of Daling Bar- Reported 6,000 by 200 Surface of sod, all-weather for all 8° 20" N, rio, 8 miles east of Del Monte No. feet north to south. types. Slope to south. Good cover 124° 54' E (approx.) 1. Elevation estimated 1,500 feet. for small aircraft. 25. Del Monte No. 4 HLG Near Impasugong barrio, 15 miles Reported 6,200 by 300 Sodded. Suitable in all-weather for 8° 16' N, southeast of Del Monte No. 1. Es- feet north to south. all types of aircraft. Limited cover 124° 59' E (approx.) timated elevation 1,800 feet. for dispersal. 26. Del Monte No. 5 MLG On west bank near headwaters of Two east to west runways, Good cover available for dispersal. (Palais) 8° 21' N, second south tributary to Tagoloan adjacent, each 5,000 by No other information. 124° 49" E (approx.) River, 1 mile south of Del Monte 300 feet. No. 1. Page I 38 BRIEF TABLE 1. 5 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 27. Del Monte No. 6 MLG Near Del Monte Club, 2½ miles Reported 5,000 by 300 Turf, all-weather. Good cover for (Tigiptip) southwest of Del Monte No. 1. Es- feet north to south. dispersal. 8° 21' N, timated elevation 1,500 feet. 124° 47' E (approx.) 28. Del Monte No. 7 HIG One mile south of Del Monte No. Reported 6,200 by 300 Turf, all-weather, for all types of 8° 21' N, 1. Estimated elevation 1,500 feet. feet northeast to south- aircraft. At least 1 bombproof 124° 49' E (approx.) west. hangar in mountain at south end of field. 29. Del Monte No. 8 FLG One mile northeast of Dalirig near Reported 4,000 by 300 Grassy sod, all-weather, drainage 8° 21' N, Agusan-Impasugong Road; 8 miles feet north to south. presumably good. Good cover for 124° 54' E (approx.) east of Del Monte No. 1. fighter aircraft nearby. Road and telephone communication. 30. Dipolog 8° 36' N, HLG One mile north of Dipolog: 9 miles Reported 6,562 by 197 Sodded, all-weather for all types of 123° 21' E south-southwest of Tagolo Point. feet northeast to south- aircraft. Good drainage. Dispersal west. for 9 heavy bombers, 25 fighters. Paved road to Puluan port. 31. Gingoog 8° 49' N, FLG Three and one-half miles south of Runway 3,400 by 150 feet Sodded ground, soft after rain. Dis- 125° 06' E Gingoog on Gingoog Bay on north northeast to southwest. persal for 25 fighter aircraft. Stand- coast of Mindanao Island. and gauge railroad to deep water port at Anakan. 32. Iligan 8° 15' N, FLG About 1,000 feet north of Mandu- Runway 4,000 by 300 feet Grass surface, soft in wet weather. 124° 15' E lug River mouth on Iligan Bay, 1 east to west. Ample cover nearby. mile north of Iligan. 33. Kabacan 7° 09' N, ELG One and one-half miles south of Approximately 750 by Believed wet and dangerous. Am- 124° 49' E (approx.) Pulangi and Kabacan River junc- 150 feet. ple cover nearby. tions near Kabacan. 34. Kibawe 7° 30' N, ELG At Kibawe, 51 miles southeast of Runway 2,624 by 246 feet Sodded clay loam, all-weather. Am- 124° 59' E Lake Lanao, 52 miles northwest of north to south. ple cover nearby. Davao. 35. Labo 8° 11' N, MLG Near Labo barrio, 4 miles north- Reported 4,642 by 328 Grass sod on sandy loam. All- 123° 49' E (approx.) west of Misamis at the southwest feet. weather. Suitable for all types of end of Iligan Bay. aircraft. Ample cover. Paved road to Port Misamis. 36. Dansalan-Maguire FLG At Camp Keithley, 1/2 mile north- Runways 2,297 by 180 feet Sodded, all-weather, good drainage, 8° 01' N, west of Lake Lanao, 2 miles west of north to south; 2,297 by 2.2% down-grade to south. Mili- 124° 17' E Dansalan. Elevation 2,455 feet. 164 feet northwest to tary barracks and other buildings at southeast. Camp Keithley. 37. Makar 6° 06' N, ELG On west shore near north end of Reported 1,950 by 651 Smooth, sandy turf. Limited cover 125° 09' E Sarangani Bay, near Makar River feet. nearby. mouth and Makar Barrio. 38. Malabang 7° 38' N, HLG Three miles north of Malabang on Runways 7,500 by 300 Smooth sand, all-weathe?. Also re- 124° 04' E north shore of Illana Bay in south feet east to west, 4,500 by ported as grass on coral base. Ex- Mindanao Island. 300 feet north to south. tensive natural cover. 39. Malangas 7° 36' N, ELG Near Malangas barrio in Zamboan- Approximately 1,500 by Sodded, possibly extensible. Ample 123° 02' E (approx.) ga Province, on west shore of Du- 200 feet. cover nearby. Waterway and roads manquilas Bay. to Zamboanga. Radio and tele- graph in Malangas. 40. Malaybalay FLG At Mamala barrio, 2 miles west of Runways, 2,370 by 300 Sodded loam, all-weather, excellent 8° 02' N, Malaybalay; elevation 2,050 feet. feet northwest to south- 125° 06' E drainage. Suitable for light aircraft. east; 3,400 by 300 feet Near road to Davao, Del Monte, northeast to southwese. and Cagayan. 41. Maramag No. 1 FLG Just south of Maramag, 53 miles Reported 3,000 by 300 7° 44' N, Grass surface, soft after heavy rain east-sourheast of Maguire Field on feet east to west. 125° 00' E but drainage good. Used in 1942 Lake Lanso. Elevation 1,550 feet. by P-40s and B-25s. 42. Maramag No. 2 MLG Near Maramag about 500 feet east Reported 5,000 by 250 7° 44' N, of Maramag No. 1. Grass surface, soft after heavy rain feet north-northwest to 125° 00' E (approx.) but drainage good. Used in 1942 south-southeast. by P-40s and B-25s. BRIEF Page I 39 TABLE I 5 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 43. Maramag No. 3 HLG 7° 43' N, Two miles south of Maramag No. Runways 6,000 by 500 1. During April, 1943, a 3-inch 125° 01' E (approx.) feet east-northease, 4,000 gravel surface was being laid on by 500 feet north to south. the north to south runway. 44. Maraut River (Pan- ELG In wooded canyon on bank of Ma- tukan) 7° 19' N, Reported 3,000 by 197 Area limited by canyon. Upgrade raut River near Pantukan, 20 miles feet east to west. 125° 57° E to east, landings from west and northease of Bassa Point on Samal take-offs from east only. Sodded Island in Davao Gulf. clay loam. Good cover. 45. Midsayap 7° 10' N, FLG Three miles south of Midsayap, 5 Reported 5,249 by 328 124° 32' E (approx.) Drainage poor. Good cover avail- miles southease of Lake Labas. Es- feet east to west. able. timated elevation 200 feet. 46. Mount Maturum MLG Seven miles northwest of Mount Reported 4,921 by 262 6° 26' N, Level and rolled with gravel. Soft Maturum in Cotabato Province, 18 feet north to south. when wer. Hills to south. Best ap- 124° 58' E (approx.) miles southeast of Lake Buluan. Es- proach from north. Only cover at timated elevation 1,500 feet. north end of field. 47. Pikit 7° 04' N. ELG One mile north of Pikit-Pagalun- Approximately 700 by Possibly extensible. Limited cover. 124° 40' E (approx.) gan barrio, 35 miles east-southeast 200 feet north to south. of the mouth of Mindanao River. 48. Placer-Badas ELG Near barrio of Basas, 2½ miles Runways, 2,625 by 164 All-weather. Northeast to south- 9° 38' N, west of Plaur, 7 miles north of feet east to west, 2,297 by west runway paved, east to west 125° 33' E Mainit Lake. 98 feet northeast to south- runway soft when wet. Ample west. cover. Buildings. Access by road and waterway. 49. Santa Cruz ELG Eight miles north-northeast of San- Reported 2,600 by 650 Limited cover nearby. No other de- 6° 56' N, ta Cruz, 14 miles southwest' of Da- feet. tails. 125° 25' E vao. 50. Valencia No. 1. MLG Two miles north of Valencia Bar- Reported 5,280 by 900 Sodded clay loam. Serviceable in all- 7° 50° N, rio, 14 miles south of Malaybalay. feet north to south. weather. Good cover nearby. 125° 05' E, Elevation 1,032 feet. (Based on AAF chart 855 AI) 51. Valencia No. 2 MLG Near Mailag, 4 miles north of Va- Reported 5,249 by 328 Cogon grass turf. Good drainage. 7° 53' N, lencia on east side of Valencia-Ma- feet northeast to south- Serviceable in all-weather for all 125° 06' E (approx.) laybalay highway. Estimated eleva- west. types of aircraft. tion 1,850 feet. 52. Wolfe Field FLG At Calarian barrio 4 miles west of Runway 2,296 by 197 feet. Sodded ground, serviceable in all- 6° 56' N, Zamboanga on southwest tip of weather. Good cover nearby. 122° 02' E Mindanao Island. 53. Zamboanga HLG Just east of the town of Zamboan- Three strips reported 7.- The existence of this new large 6° 55' N. ga on southwest tip of Mindanao Is- 000 by 400 feet, 7,000 by landing ground has not been con- 122° 07' E land. 400 feet, 4,000 by 400 firmed. feet. Sector D: Sala Archipelago 54. Zettel Field (Jolo) FLG On northwest coast of Jolo Island, Reported 3,960 by 459 Sodded clay loam. Serviceable in 6° 03' N, 1 mile east of town of Jolo. feet east to west. all-weather. Cover nearby. 121° 01' E Sector E: Northeast Borneo 55. Jesselton HLG On northwest coast of North Bor- Various reports. May not Fuel, oil, water and some repair 5° 57° N, neo, 3 miles west of Jesselton. be actually constructed. facilities available. Radio station 116° 04' E Also two 7,000 foot run- and accommodations at Jesselton. ways reported. 56. Kenigau 5° 21' N, ELG Exact location unknown; reported Reported 3,300 feet Sandy soil covered with alang 116° 12' E (town) to lie between 2 spurs of low hills. square, exact dimensions (heavy grass). No other details. unknown. 57. Kudar 6° 56' N, ELG Three and one-half miles north of Unknown. Details unknown. Reported a mili- 116° 50' E Kudat on the northwest coast of tary field and considered opera- Marudu Bay at north end of west tional. arm of North Borneo. Page I 40 BRIEF TABLE 1.5 (Continued) NAME AND COORDINATES CLASSIFICATION LOCATION DIMENSIONS REMARKS 58. Labuan Island FLG Reported on Labuan Island which Varying reports of 2 run- Two aircraft observed here accord- 50 20' N, lies off the west coast of British ways, longest 6,000 feet; ing to recent intelligence. No other 115° 13' E (approx.) North Borneo. also that both are 6,000 details. feet. 59. Lahad Datu ELG Reported at Lahad Datu in west Unknown. No other details but field is con- 5° 02' N, corner of northernmost reach of sidered operational. 118° 20' E (town) Darvel Bay on the Southeast coast of Borneo. 60. Ranau 5° 58' N, ELG Exact location unknown. Ranau is Unknown. Reported that development was 116° 42' E (town) reported in West Coast Residency 1 unlikely. Also reported that it is mile east of confluence of Ligwau now considered operational. and Berambang Rivers. 61. Sandakan ELG Reported at Sandakan on the west Unknown. Details unknown; development in- 5° 51' N, side of the entrance to Sandakan to a major base expected; consider- 118° 07" E (town) Harbor on the northeast coast of ed operational. Borneo. 62. Tarakan 3° 20' N, ELG In central part of southwest coast of Runways 2,850 ft. north- Firm earth and grass usually serv- 117° 34' E Tarakan Island, 5 miles north- east to southwest, 2,520 iceable; fuel and oil available; fa- northwest of Tarakan. feet east to west, 2,430 cilities for minor repairs. Dutch feet northwest to southeast, had 4 fighter and 4 bomber rever- 2,310 feet north to south. ments here. 63. Tawau 4° 15' N, ELG Reported at Tawau on north shore Unknown. Details unknown but it is con- 117° 53' E (town) of entrance to Cowie Harbor on the sidered now to be used for opera- southeast coast of North Borneo. tional purposes. Sector F: Northern Celebes 64. Langoan 1° 09' N. FAD One mile east-northeast of Lan- Reported 4,200 by 300 Surface coral or limestone, proba- 124° 50° E goan, 3 miles west-southwest of feet north-northeast to bly all-weather. Extensible. Disper- Kokas at the south end of Lake south-southwest. sal for 40 fighters, 30 bombers. Tondano. Buildings nearby. Mountains in area. 65. Mapanget 1° 31' N, FLG One and three-fourths miles west of Information varied, Grass surface. Reported capacity 124° 54' E Mapanger, just north of Mapanget (Topic 124, F, (3), (b)) 20 fighters, 40 bombers. River and south of Kima River, 6 miles east-southeast of Manado. TABLE I 6 POSSIBLE AIRFIELD SITES Sector A. Halmabera NAME APPROXIMATE COORDINATES REMARKS 1. Akelamo 1° 28' N. 128° 40' E. Small coconut plantation, 62 acres near Akelamo; ground flat and dry; soil, sandy. 2. Belangbelang I. 1° 19' S. 127° 24' E. Possible site a mile long northwest to southeast on northeast side of the island. 3. Bisa L 1° 15' S. 127° 28' E. Possible strip reported at southwest end of Bisa Island, which is 13 miles north of west end of Obi Major Island. 4. Boeli-Serani 0° 52' N. 128° 17' E. Clearing for possible strip reported inland from Boeli-Serani, north coast of Boeli Bay. 5. Djailolo North 1° 09' N. 127° 28' E. Five miles north-northeast of Djailolo; cleared for 1650 feet by the Dutch in 1941; not strip. developed; extension possible in all directions; a good deal of levelling required on this 6. Djailolo South 1° 07' N. 127° 28' E. Three and one-fourth miles north-northeast of Djailolo; cleared for 5280 feet by the Durch in 1941; not developed; extension possible east-west. 7. Galela East 1° 48' N. 127° 53' E. Possible clearing for strip reported 7 miles east-southeast of Galela medium bomber airfield, 3 miles east-southeast of Galela; unconfirmed. 8. Morotai I. 2° 06' N. 128° 31' E. Possible strip reported on southeast end of Morotai Island; unconfirmed. 9. Sidangoli 0° 54' N. 127° 31' E. Possible site, runway limited to 4000 feet (approximately) northeast-southwest; near Sidangoli at northwest end of Dodinga Bay. BRIEF Page I 41 TABLE I 6 (Continued) NAME APPROXIMATE COORDINATES REMARKS 10. Sofifi 0° 44' N. 127° 33' E. Clearing for strip reported but not confirmed, 1 mile south of Sofifi. (town) 11. Tilope 0° 13' N. 127° 55' E. Possible site on coastal plain near Tilope village, on the east coast of south arm of Hal- mahera Island. Land is flat, dry, and sandy near the shore. 12. Tobelo 1° 39' N. 128° 00' E. Possible site on coastal plain 5 miles south of Tobelo, 15 miles southeast of Galela, on east coase of Halmahera Island. Ground reported flat, firm, and well drained. 13. Wajaoea 0° 45' S. 127° 39' E. Possible site about 1 mile northeast of Wajaoea village, on south side of ischmus on Batjan Island. 14. Wasile 1° 04' N. 127° 59' E. Probably just north of Wasile town, on northeast coast of Kaoe Bay: "serviceable (town) strip" reported but not confirmed. Sector B. Sangibe-Taland 15. Karakelong I. 4° 00' 4° 35' N. A few flat areas along the coast; no detailed information. 126° 33' 126° 55' E. 16. Tamako 3° 28' N. 125° 30' E. Possible sites reported near Tamako on the southwest coast of Sangihe Island. Sector C. Mindanso 17. Camp Overton 8° 12' N. 124° 12' E. Possible site reported at Camp Overton at the head of Iligan Bay; flat, cleared area on (town) the coast. 18. Dalwangan 8° 06' N. 125° 04' E. Possible site reported at Dalwangan; outside of town parallel to a road. 19. Davao (Japanese 7° 17' N. 125° 41' E. Approximately 15 miles north-northeast of Davao in the midst of a Japanese Colony, Colony) a natural landing field 6000 feet by 7000 feet. 20. Davao Gulf 6° 30' N. 126° 07' E. Any amount of flat land which could be cleared and used as a landing ground; on the east coast of Davao Gulf, in the general vicinity of Madruka Point. 21. Dapitan 8° 39' N. 123° 26' E. Porential site just in front of the church at Dapitan, on the north end of Mindanao (town) Island, about 1200 feet by 1500 feet, running down to the water, could be made into a small field. 22. Dayana Point 7° 39' N. 123° 08' E. Potential site reported on Dayana Point on the south central coast of Mindanao; on the northeast coast of Dumanquilas Bay; the land slopes gently back from the end of the point for a distance of about 1 mile. 23. Dumanquilas Bay 7° 04' N. 123° 01' E. Potential site just northwest of Bacao, just southwest of Boton; 3000 feet by 1500 feet nearly level but needs clearing; good approaches. 24. Igai Point 7° 38' N. 123° 03' E. Potential site reported on Igai Point on west side of Dumanquilas Bay on south side of Mindanso Island; on a 100 foot plateau which tops the point; reasonably flat, needs clearing: drainage considered excellent. 25. Malalag 6° 36' N. 125° 23' E. Flat area to the southwest of Malalag which is on the southwest coast of Malalag Bay, east of Dávao Gulf; needs to be cleared. 26. Malamaui I, 6° 43' N. 121° 58' E. Potential site reported on Malamaui Island, just northwest of Basilan Island; landing field could be cleared at a neighboring rubber plantation but would entail considerable work. 27. Murcielagos Bay 8° 35' N. 123° 34' E. Sites are located in the vicinity of the cultivated areas on Diuyu River; at the South end of Murcielagos Bay. 28. Nasipit Harbor 8° 59' N. 125° 26' E. Potential site reported at Nasipit Harbor on the northwest coast of Mindanao Island; (town) sufficient level ground DO permit clearing and levelling for a landing ground. 29. Polloc Harbor 7° 23' N. 124° 16' E. Small emergency landing ground could be made from the parade ground at the con- (town) stabulary post at Parang by removing the radio poles; on the central east coast of Polloc Harbor. 30. Port Holland 6° 33' N. 121° 52' E. Potential site reported at Port Holland in A large area filled and packed with sawdust; on the west coast of Basilan Island. 31. Port Misamis 8° 10' N. 123° 51' E. Two excellent sites about 1/2 to 2 miles in area reported on the road berween Misamis and Clarin; at the southwest end of Iligan Bay. 32. Port Sibulan 7° 33' N. 122° 54' E. Potential site reported at the head of Port Sibulan on the south coast of Mindanao Island; could be prepared at considerable cost by clearing the necessary land. Page I 42 BRIEF TABLE 1 6 (Continued) APPROXIMATE COORDINATES REMARKS NAME 33. Sapali 6° 18' N. 124° 43' E. Possible site reported at Sapali which is 1/2 mile northeast of Alah River; 6 miles north- (town) west of Lake Sultan; about 23 miles south-southwest of Lake Buluan. 34. Sindangan 8° 14' N. 123° 00° E. Potential landing field reported at Sindangan; in the northeast corner of Sindangan (town) Bay; 11/2 miles north of mouth of Sindangan River. 35. Sumilao 8° 17' N. 124° 56' E. Potential sise reported at Sumilao which is 20 miles southwest of the head of Maca- (town) jalar Bay. Sector D. Sulu Archipelago 36. Banaran 1. 5° 01' N. 120° 08' E. Area is well cleared and could be prepared easily on Banaran Island in the Tawitawi Island Group. 37. Bubuan 1. 5° 25' N. 125° 35' E. Potential site on Bubuan Island in Tawitawi Group; best cleared areas are on the north side of the island. 38. Carmen Point 5° 05' N. 119° 50' E. One mile east of Carmen Point, on the west coast of Tawitawi Island, an area which could be levelled. Reported as the best spot in the Tawitawi Islands for building and maintaining a landing field. 39. Manalik Channel 5° 05' N. 119° 50' E. A landing ground could possibly be constructed on the east side of Manalik Channel berween Carmen Point and Lapidlapid; area only 75% cleared. 40. Papahag I. 5° 02' N. 119° 48' E. Potential site reported in the center of Papahag Island, at the south end of the Tawitawi Group; area is flat and could easily be cleared. 41. Sanga Sanga 1. 5° 04' N. 119° 48' E. North of Malasa Point, site about 1 mile square may be prepared in less time than any other point in the Tawitawi Group; Sanga Sanga Island is one of the southernmost in the Tawitawi Group. 42. Secubun L 5° 06' N. 120° 18' E. The east central side of the island can easily be cleared to form a landing field 1 mile by 1/2 to % mile. The soil is coarse loam with chalky sub-soil at about 18 inches. Secu- bun Island is 4½ miles southeast of Tawitawi Island. 43. Simunul I. 4° 53' N. 119° 51' E. Cleared spaces are available on both east and west sides of the island which is 9 miles south of Tawitawi Island. In 1929 a naval reconnaissance estimated that in three weeks with local Simunal labor a large-sized landing field could be cleared. 44. South Ubian I. 5° 10' N. 120° 30' E. Potential site which could be levelled in a reasonably short time, rich loam soil with a tendency to fine coral and sand toward the shore. Cleared spaces are firm. About 17 miles east of Tawitawi Island. 45. Tabawan I. 5° 13' N. 120° 35' E. Reported probably the flattest island in the Tawitawi Group, areas on both north and south shores where a small plane could take off. Sector F. Northern Celebes 46. Amoerang 1° 11' N. 124° 33' E. Possible site reported around Amoerang Bay to the west and along the coast from (town) Amoerang. 47. Belang 0° 56' N. 124° 47' E. Possible site reported at Belang on the south side of the north arm of the Celebes; coconur plantations along the shore. 48. Bongo 0° 42" N. 122° 30' E. Possible sizes reported in low flat areas along the coast; in valley of Pagoejaman River near Bongo. 49. Dondo Bay 0° 52' N. 120° 22' E. Possible site on a low flat shore covered with mangroves and coconut plantations on south side of inlet on west side of Dondo Bay. 50. Gorontalo 0° 30' N. 123° 03' E. Possible site in Pagoejaman valley about 30-40 miles from Gorontalo. 51. Kema 1° 22' N. 125° 05' E. Possible site reported at Kema on east side of north tip of the Celebes; on A low plain (town) covered with coconut plantations and scattered mangrove. 52. Kotaboena 0° 48' N. 124° 39' E. May be same as Kotaboenan (coordinates given); low ground with protected anchor- (town) age behind islands. 53. Limba 0° 29' N. 122° 32' E. Existence doubtful, unconfirmed. 54. Leok (Bilang Bay) 1° 09' N. 121° 25' E. Possible site about 3 miles southeast of Leok on southwest side of Bilang Bay; flat shore but area is rather marshy. 55. Tamboe Gulf 0° 01' N. 119° 54' E. Low sandy shores planted with coconuts on Tamboe Gulf. 56. Toeladenggi 0° 45' N. 121° 52' E. West in the direction of Cape Santigi some flat stretches of coast line with scattered jungle of coconut plantations. FIGURE 1.7 JANIS 155 CELEBES SEA AREA swar as TERRAIN REGIONS MINDANAO sit NORTH Sector Boundary 3 P ACIFI 17 STATUTE 5 of - 1 . U € o C E A N S 9 - ROUTABAN GROUP F TAPARTANA SULU ARCHIPELAGO AND BASILAN ISLAND Cape for - Cap : - } PL imps TARA D MINDANAO AND.AD.,CENT SLANDS GLOSSARY SEU ACORDADO I MANGAM a. C - GROUP KAWNO % Ambore BLANDEN ANDS 2 TALAMO BLANDEN à I E SANGHE-TALAUD ISLANDS I CELEBE S SEA B 3 TERN BORNBOYANG ADDRESS ISLANDS A w HALMAHERA AND ADJACENT ISLANDS B F E NORTHERN CELEBES AND ADJACENT ISLANDS 3 ZEE TERMATE 5 I - , VAN To \ GOLF VAN TOMINI GOBAISA Online BLANDEN OF / NALMAHERA s HALMAHERA GORONTALO BLANDEN FIGURE 1. 8 IANIS 155 CELEBES SEA AREA MANAT GUIF STRATEGIC TERRAIN CABATAM MINDANAO w NORTH Areas of low relief Major Relief Borriers (General Trand) Major Swamp Borriers Natural Routes of Movement [wis Posses, Defilies and Corridors) PACIFIC E - M. OCEAN - S U GULF 1) DROUP 1 FANDUTARAN GROUP Ta Caps las xxo, - I Them GLOSSARY a TE H f. Trace Bay e SAMANGAM a. B Supert SEU ABOVELADO - % Cape EAWIO Ta BLANDEN TALAID BANDEN % 3 CELEBE. S SEA 3 > B E , ZEE There TERMATE 5 To VAN - Ta. DOBAISME GOLF VAN TOMINI BLANDEN - OF + HALMAHERA GORONTALO BOWLDPAD " BALIKFAPAN Lar FIGURE 1-9 JANIS 155 CELEBES SEA AREA SOIL TRAFFICABILITY NORTH MINDANAO SULU S E A PACIFIC I STATUTE an of - IM fundary un or MINDANAO IF USE SOUTH CHINA SEA OCEAN Cajayes - - Date of - - # DiD MINDANAO FAMOSTARAN GROUP - - - - - of I I © I EXPARTANA GROUP - I - - - - a I 1 - - - I - AREA E - : I - BULU - I - I - GROUP - - and - - - - - TAPA DROUP - - CROUP . - Denvel - - United - Marie - MAHERA AND TALAUD - - Endo * LEGEND a - BORNEO - - TALAUD BLANDEN - e - - I I 2 - - - - , I I - at - - I I - . - - tais - I I I - - - - - - - - 0 - 1 - E - : - I - Il ) - I a I - - I - - . 2 I . . Bangibe - - - - 1 - & a I C ELEBE S SEA a / AREA % - NORTHERN CELEBES & - - Di - - - sous NOT MAPPES E - 2 BORNEO i - Merchal L. - - - D & sous NOT MAPPED - I s ZEE a HALMAHERA 5 BOLLS NOT WAPPED MAKASSAR 0 + VAN C E E 8 5 GOLF VAN TOMINI F.Om OF HALMAHERA GORONTALO o STRAT M LOO - 114° dr or - FIGURE 1 - 10 JANIS 155 III" IF - CELEBES SEA AREA MANAY are STRATEGIC ROUTES CABATAN MINDANAO sh NORTH Strotegic routes possoble No motor traffic Strategic - Other routes of possible value E APACIFIC STATUTE 5 0 will 1 114° * U OCEAN S GULF - DIVAO Cape for Apalin impo GLOSSARY by BARANGAN a. » € - SAU - - - I - - - - - , - 1 - . CELEBE . S A - - - v I I - - - - - & F. I ZEE 5 VAN WEZH GOLF VAN TOMINI . OF - is $ - Tabe I' r - HALMAHERA I GORONTALO BALEFAPARAN Der FIGURE 1.11 IANIS 155 CELEBES SEA AREA PORT FACILITIES - Major Parts Minor Parts The - - - - Immiry el - m E I FIGURE 1-12 JANIS 155 CELEBES SEA AREA NAVAL AND AIR FACILITIES = © Il 12 11 = - (5) n o by ... I of E m - Table of Contents-Continued Page Page 15. TRANSPORTATION AND COMMUNICATIONS I-25 C. Mindanao sector and Sulu Archipelago I-27 A. Transportation I-25 D. Northeast Borneo I-27 (1) Railroads I-25 (2) Roads and trails E. Northern Celebes sector I-25 I-28 (3) Water transport I-25 18. HEALTH AND SANITATION 1-28 B. Communications I - 25 A. Diseases I - 28 (1) Radio I-25 B. Water (2) Telegraph, telephone, and submarine cable I-25 I-29 C. Sanitation I-29 16. RESOURCES AND TRADE I-26 D. Public health I-29 A. Food resources I - 26 E. Hospitals and medical personnel I - 29 B. Water supply I-26 F. Food I - 29 C. Construction materials I-26 G. Insects and animals I-30 D. Industrial raw materials and primary processing I-26 (1) Minerals I-26 19. NAVAL AND AIR FACILITIES I-30 (2) Fuels I-26 A. History and development I-30 (3) Agricultural and marine materials I-26 B. Organization 30 E. Manufacturing plants I-26 (1) Administration I-30 F. Electric power I - 26 (2) Tactical 30 G. Commerce I - 26 (3) Disposition of forces 1-30 H. Finance I-27 C. Supply and maintenance I-30 (1) Depots I-30 17. PEOPLE AND GOVERNMENT I - 27 (2) Supply routes I- 30 A. Halmaherá sector I - 27 D. Naval facilities I- 31 B. Sangibe-Talaud sector I-27 E. Air facilities I-31 Confidential DECLASSIFIED By Authority of JCS letter, 7.25-75 By SR Date JUL 01 1975 JANIS 155 1 Non-registered CHAPTER II JAPAN CHINA MIDWAY IS. HAWAIIAN . IS. HONOLULU WAKE 1. MARIANAS IS. JOHNSTON I. PHILIPPINE FRENCH-INDO IS. GUAM CHINA /PALAU MARSHALL #15. CAROLINE ISLANDS GILBERT IS. BORNEO CHRISTMAS I. CELEBES NEW GUINEA JAVA SOLOMON IS. TIMOR AUSTRALIA JOINT ARMY-NAVY INTELLIGENCE STUDY OF CELEBES SEA AREA MILITARY GEOGRAPHY DECLASSIFIED By Authority of MAY 1944 JCS letter, 7-25-75 By SR Date JUL 31.1975 ECLASSIFIED By Authori of JCS letter, 7-25-75 By SR Date JUL 1975 List of Effective Pages, Chapter II CHANGE IN Sunject MATTER Erract PAGE NUMBERS Cover Page Original unnumbered List of Effective Pages and Table of Contents, Chapter II (inside front cover) Original unnumbered Text and Figures Original pp. II-1 to II-40 Figure (insert, reverse blank) Original Figure II-42 Figure (insert, reverse blank) Original Figure II-43 Figure (insert, reverse blank) Original Figure II-44 Figure (insert, reverse blank) Original Figure II-45 Inside Back Cover (Table of Contents, cont'd) Original unnumbered Back Cover (outside blank) Original unnumbered Table of Contents Note: This chapter is based on material available in Washington, D. C., on 25 April 1944. Page Page 20. GENERAL DESCRIPTION OF THE AREA II 1 C. Mindanao and adjacent islands II 24 A. Relief II 1 (1) Rivers II 24 B. Drainage and water supply II 1 (2) Lakes II 24 (1) Rivers II 1 (3) Swamps II 25 (2) Swamps II 1 (4) Water supply II 25 (3) Lakes II 1 D. Sulu Archipelago II 25 (4) Water supply II 1 E. Borneo and adjacent islands II 25 C. Vegetation II 1 (1) Rivers II 25 21. RELIEF (2) Lakes II 26 II 2 (3) Swamps II 26 A. Halmahera and adjacent islands II 2 (4) Water supply II 26 (1) Southern Halmahera II 2 F. Celebes and adjacent islands II 26 (2) Central Halmahera II 2 (1) Rivers II 26 (3) Northern Halmahera II 2 (2) Lakes II 26 (4) Morotai Island II 3 (5) Western Volcanic Islands (3) Swamps II 26 II - 4 (6) Batjan Islands II 4 (4) Water supply II 26 (7) Lesser islands II 5 23. SOIL TRAFFICABILITY II 26 B. Sangihe-Talaud Islands II 5 A. General factors affecting soil trafficability II 26 (1) Sangihe Islands II 5 B. Soil trafficability in Halmahera II 27 (2) Talaud Islands II 5 C. Sangihe-Talaud Islands II 27 C. Mindanao and adjacent islands II 5 D. Mindanao II 27 (1) Southern Mountain Region II 6 (2) Central Mountain Region II 6 E. Sulu Archipelago II 28 (3) Davao Lowlands II 6 F. Northern Borneo II 28 (4) Eastern Mindanao Region II 6 G. Northern Celebes II 29 (5) Agusan Basin II 8 (6) Bukidnon Uplands 24. VEGETATION II 29 II 9 (7) Lanao Uplands II 10 A. Natural vegetation II 29 (8) Western Mindanao II 12 (1) Rain forest II 29 (9) Cotabato Basin II 12 (2) Second growth II 30 (10) Adjacent islands II 12 (3) Moss forest II 30 D. Sulu Archipelago and Basilan Island II 13 (4) Mangrove swamp II 30 (1) Basilan Island (5) Nipa swamp II 30 Il 13 (2) Jolo Island (6) Swamp forest II 30 II 13 (3) Tawitawi Island (7) Marsh grass, sedge, and wild cane II 31 II 13 (4) Lesser islands (8) Open grassland II 31 II 13 E. Northern and Eastern Borneo (9) Special types of vegetation II 31 II 13 (1) Dutch Borneo (north of the Equator) B. Cultivated lands II 31 II 14 (2) British North Borneo II 15 (1) Plantations II 32 (3) Adjacent islands (2) Cultivated fields II 32 II 19 F. Northern Celebes and adjacent islands II 19 C. Distribution of vegetation in Halmahera II - 32 (1) Minahasa-Bolaäng-Mongondow Region II 19 (1) Southern Halmahera II 32 (2) Northern Peninsula (2) Central Halmahera II 32 II 21 (3) Adjacent islands II 23 (3) Northern Halmahera II 33 (4) Morotai Island II 33 22. DRAINAGE AND WATER SUPPLY II 23 (5) Western Volcanic Islands II 33 A. Halmahera and adjacent islands II 23 (6) Batjan Islands II 33 (1) Rivers II 23 D. Vegetation distribution in Sangibe-Talaud Islands II 33 (2) Lakes II 24 (3) Swamps E. Vegetation distribution in Mindanao II 33 II 24 (4) Water supply (1) Southern Mountain Region II 33 II 24 (2) Central Mountain Region II 33 B. Sangibe-Talaud Islands II 24 (3) Davao Lowlands II 34 (Continued inside back cover) Chapter II Page Il I MILITARY GEOGRAPHY 20. General Description of the Area along with their susceptibility to flooding, make them effective obstacles to overland routes from one coastal objective to an- A. Relief. other. Outside Borneo, there are only two rivers that would (FIGURES II 42 and II - 43). be sufficiently large to act as defensive phase lines for large-scale operations; these are the Agusan and Mindanao-Pulangi rivers Most of the land in the Celebes Sea area consists of rough, on the island of Mindanao. mountainous terrain, especially in the interior of the islands. Areas of low flat land are found mainly along the coasts or on (2) Swamps. flood plains of the larger rivers in Borneo and Mindanao. The Even more effective than the rivers as barriers to cross-country coastal plains are usually narrow, and seldom are continuous movement are the swamps and marshes. Practically all the ex- for long distances. Cross-country military operations will have tensive ones are located on the flood plains of the large rivers of to contend with difficult terrain problems throughout the area, Borneo and Mindanao, but often no less significant are the with few exceptions. These exceptions are in the Minahasa Re- small stretches of poorly drained land that lie back of the gion of Celebes (the northeastern tip of the northern penin- beaches on many of the coastal plains. They restrict coastal sula), and the central portion of Mindanao where there are travel to narrow beach strips, and effectively limit the area of wide stretches of open, rolling terrain. Elsewhere, the interiors flat land suitable for airfields. of the islands under consideration are mountainous, covered (3) Lakes. with dense forests, sparsely inhabited by native populations, and There are few lakes in the area, and most of these are either accessible only by forest trails. For this reason, most military small ponds in volcanic craters or shallow swamp lakes on river operations will be directed against peripheral objectives, pri- flood plains. The only ones that appear to be suitable for float marily against airfields, harbors, supply points, and garrison plane use are Lakes Lanao and Mainit on Mindanao, Galela bases along the coasts. Nearly all such objectives are located on Lake on Halmahera, and Tondano on Celebes. comparatively narrow and discontinuous coastal plains without good exits inland. In a few cases, particularly in northeastern (4) Water supply. Borneo, there are extensive river flood plains extending inland Since all of the area has a considerable rainfall, and because from the coast, but these are likely to be swampy, heavily forest- there are innumerable streams that have their headwaters in ed, and not suitable for large scale operations. Because of the mountainous country, fresh water is almost always available. peninsular character of the larger island masses included within The main exception to this is found on the very small islands, the area, attention also will likely be focussed upon cross-island particularly those of the low coral or sandy type. Usually on such routes, control of which will enable troops to cut off relatively islands the only available fresh water is obtained either from the large segments of the islands. These routes, with few excep- collection of rain water or from shallow wells. tions, follow mountain passes, and undoubtedly have numerous associated defensive phase lines. Very few of these passes are C. Vegetation. now utilized by motor roads, and it is doubtful if many are suited for road construction. Wide expanses of unbroken forest are characteristic of nearly Although there are hundreds of smaller islands within the all of the rough mountainous sections. On the coastal lowlands, area, relatively few are militarily significant-chiefly those that however, the type of vegetation is dependent largely on soil are low, flat, and suitable for airfield development or for minor conditions and on the stage of cultural development of the area, land bases. Several such islands are located off the east coast of As a general rule, low, sandy coastal plains contain groves of Halmahera, and in the southern portion of the Sulu Archi- coconut palms. Back from these sandy soil areas, the coastal pelago. lowlands contain variable amounts and types of cultivated land. On Halmahera, Borneo, and many of the smaller islands sparsely B. Drainage and water supply. populated with native peoples, the lowland plains vegetation is likely to consist of scattered native gardens, abandoned clearings (1) Rivers. grown up to tall coarse grass ("kunai" or "cogon"), dense The rivers generally are short and rapid, because of their secondary forest, or patches of sago (particularly in the small drainage basins and the absence of broad lowland plains. swamps). In culturally more advanced portions of the area The main exception to this is in Borneo, particularly in the (Celebes and Mindanao), open fields are much more common, eastern and northeastern portions, where a broad area of and are used mainly for rice and corn. Large plantations are hilly to mountainous terrain in the interior receives heavy relatively rare outside of Mindanao. Intermediate slopes, or low, rainfall, and is the source region of many large rivers. In their hilly lands, commonly are in either secondary forest or scattered lower reaches these rivers are deep and follow winding courses clearings. Mindanao contains the only broad areas of open across their flood plains to the sea. They are practically the only grasslands. The Bukidnon and Lanao uplands in central Min- easy routes of penetration into the interior of this large but little danao have hundreds of square miles of grasslands, and the known island. From a military point of view, however, they act flat, interstream areas in these regions require little more than more as barriers than routes, since objectives are seldom lo- the cutting of the coarse tall grass to make them suitable for cated in the interior. The great width and depth of these rivers, airfields. DECLASSIFIED By Authority of JCS letter, 7-25-75 By SR Date Page Il 2 MILITARY GEOGRAPHY 21. Relief popo, eastward of Remdi Point, and westward of Sagea village, the coastal flats are continuous around the entire peninsula. The The major relief regions and their characteristics are indi- best crossing of the peninsula is south from the middle portion cated on FIGURES II 42 and II 43, which should be studied of the Sangadji valley to the valley that reaches the coast of concurrently with the text material below. Topographic maps Weda Bay at the village of Sepo. The maximum elevation of many sectors will be found in the plans pouch. along this trail is only 1,424 feet. (b) Central Subregion. This subregion is located at the A. Halmahera and adjacent islands. junction of the four peninsulas. In general relief structure, it is somewhat similar to the mountain block between the Kaoe Halmahera and its neighboring islands are mostly hilly to and Lamo valley (Paragraph (3) (b) below.). The western mountainous (PLANS 2, 3, and 4). Areas of flat to undulating land are small and discontinuous, and are found along the coast, escarpment, however, is much more deeply dissected, and there primarily near the mouths of the principal streams. The three are several outlying remnants of the block rising from surround- lowland areas (The Galela, Kaoe, and Djailolo-Soesoepoe ing lowlands, particularly in the southwestern portion. East of the summit the land surface is not as dissected as in the district plains) are located on the northern peninsula of the main island. The only easy cross-island route is at the narrow isthmus between west of the Kaoe valley, and there are a few rather wide upland Dodinga Bay and Kaoe Bay. The central portions of the penin- areas of low relief. The coastal plains generally are narrow, sulas have mountainous backbones, and trail crossings are usually except near the mouths of some of the larger streams, i.e., that of low utility. Large-scale military operations would be ex- at the head of the Bay of Pajahi, the southeastern side of Do- ceedingly difficult, and probably impracticable away from a few dinga Bay, the Kobe valley extending inland from the head of coastal areas, because of rugged terrain and dense forest Weda Bay, and the plain of Ekor, on the south side of Kaoe cover in the interior. For purposes of convenience in describing Bay. The lowlands generally contain a considerable proportion the relief of Halmahera it is divided into 3 regions: a southern of swamps or marshes, particularly those along the southwestern region, a central region, including the 2 eastern peninsulas and coast of this region. None of these lowlands has good natural the central part of the island; a northern region consisting of the exits to other parts of the island except, in a few cases, laterally northern peninsula. These are sub-divided into terrain sub- along the coast. The most feasible and probably the only possi- regions. The volcanic islands west of Halmahera, Morotai, and ble strategic cross-country route lies between the plain of Ekor the Batjan Group will be treated in separate paragraphs. on Kaoe Bay, and the northern portion of the Kobe Plain. Only a crude native path now follows this route, but presum- (1) Southern Halmabera. ably it would not be difficult to improve. The maximum eleva- This region includes the southern peninsula of the island. A tion along this trail is only about 700 feet. A notable character- long mountain ridge extends along the western side. The south- istic of the coastal plains is their uniform flatness. Airfield con- ern end of the peninsula is composed largely of uplifted coral struction on them generally would have serious drainage prob- reefs with rough surfaces, In a few places, such as west of Weda, lems. and east of Saketa and Ganedidalem, streams have cut gaps (c) Nortbeastern Peninsula. The mountain area that into the ridge, providing relatively easy crossings. The highest comprises most of this peninsula is not very high (generally and most rugged section is directly opposite the northeast cor- between 2,000 and 3,000 feet), but it is a confused mass of ner of Batjan Island. Mount Oewattjain rises here to an elevation ridges and valleys of irregular shape, trending in every direc- of 4,100 feet. The top of the ridge is generally between 2,000 tion. The interior is unpopulated and would be very difficult to and 3,000 feet in elevation. Since the drainage divide is near cross. West of Boeli-Serani is an extremely rugged mountain the west coast, the coastal plain on the west side is very area about 30 miles long from north to south, and 10 miles narrow or is nonexistent. Wider coastal plains with associated wide (in its northern portion). It constitutes an effective bar- coral terraces border the east coast. Extensive swamps cover large rier to any cross-country travel northwestward from Boeli Bay. segments of the plains in the vicinity of Foja and Weda on the As in other parts of the island, the coastal plains vary in width. east coast, and Maidi on the west coast. The principal ones are at the head of Wasile Bay, the Akelamo and Onat River valleys, and the plain of Boeli-Serani. There (2) Central Halmabera. are no good exits to the rest of the island, hence the military Central Halmahera consists of several terrain subregions significance of these plains lies mainly in their suitability for which are similar in general but have sufficient individual di- airfield construction. versity to merit individual description. (a) Southeastern Peninsula. The northwestern portion of (3) Northern Halmabera. this region consists of rough hill country. Toward the south- From the standpoint of relief, the northern peninsula of Hal- west, the hill country narrows to a long, narrow ridge that con- mahera is the best suited for military operations, because despite tinues to the end of the peninsula, Ngolopopo Point. The larg- the preponderance of rough, mountainous terrain, it also con- est valley in the region is that of the Sangadji River, whose mid- tains the largest areas of low slopes on the island, The major dle course opens out to form a broad interior basin. This basin alignment of the relief features is in a northeast-southwest di- is relatively inaccessible. The lower portion of the valley is al- rection. The northern peninsula can be divided into 5 subre- most a continuous swamp during the wet season. The coastal gions of relief: the Kaoe-Tobelo Lowlands and Ridges, the plains on the northern side of the peninsula are somewhat Lamo-Kaoe Block, the Central Volcanic Range, the Galela wider than those on the south side, although they are generally Plains and Tiabo Valley, and the Northwestern Mountain only a mile or so in width. Except for a few places where there Ridge. are rocky sea cliffs, such as a short distance westward of Ngolo- (a) Kaoe-Tobelo Lowlands and Ridges. The southeast- MILITARY GEOGRAPHY Page Il 3 ern side of the northern peninsula of Halmahera is a region of valley to the north, is a belt of rough country, interrupted by the open flat plains, rolling hill country, and dissected coastal Iboe plains which extend inland from the west coast for about benches or terraces. The most extensive area of plains on the 5 miles. A considerable part of this lowland is under native entire island lies within this region, in the drainage basin of the cultivation. The lowland at the head of Loloda Bay is mostly Kaoe River. The Kaoe plains can be divided into 3 segments: swampy. The southwestern end of the region is formed by a wide, well-drained lowland lying back of the village of Kaoe, Djailolo Peak, a volcanic cone 3,706 feet high. It is separated and extending inland for about 8 miles to a point near Popan from the rest of the range by a belt of low, level terrain, the where the valley is constricted; a middle portion, 11 miles long Djailolo-Soesoepoe Plain (FIGURE II . 1). This plain is fertile and 4 to 5 miles wide, much of the southern part of which is and well-populated, and the Dutch, prior to the war, had par- swampy; and in the north, an area of flat plateau country lying tially completed 2 emergency airplane landing strips on it, directly south of the volcanic range at an elevation of about about 3 miles north of Djailolo. 1,000 feet, and separated from the lower plains by a belt of (d) Galela Plains and Tiabo Valley. The Tiabo River hilly terrain. Immediately east of and facing westward toward has its headwaters not far from Loloda Bay on the west coast. the Kaoe plains is a steep escarpment. From the top of the es- It flows for most of its course through a narrow, flat-bottomed carpment, the land surface breaks away toward the east in a valley that is swampy in many places. Its lower reaches open out series of long sweeping slopes broken by numerous stream val- into the Galela plain, one of the largest and most continuous leys. The gradient of these slopes decreases gradually toward the areas of flat land on the island. This lowland is approximately coast. Along the eastern coast, from opposite Miti Island south- 8 miles long from north to south, and 5 miles wide at its widest ward to the entrance to Kaoe Bay, the coast is backed by exten- point. Two volcanic cones (965 and 685 feet in elevation) rise sive terraces between 100 and 300 feet in elevation. They are abruptly from the lowland immediately northeast of Galela deeply dissected by streams. From Miti Island northward to Lake, and dominate the eastern approaches to the plain. Most of Tobelo and beyond, there is a continuous coastal plain which, the plain is cleared and either under cultivation or in patchy at its widest point, is only about 2 miles wide. It is well drained grassland, but there are rather extensive marshes near the mouth and has a comparatively large native population. The narrow of the Tiabo River that are reported to be almost impenetrable. coastal strip between the Tobelo coastal plain and the Galela The military significance of this subregion is due to 2 relief plain is broken by a series of lava flows from Mount Mamoeja. conditions; first, the suitability of the Galela plain for airfield These flows, on several occasions, have blocked the coastal road development (a new Japanese strip is under construction be- between Galela and Tobelo. tween Galela Lake and the Tiabo River), and second, the (b) Lamo-Kaoe Block. West of the Kaoe plains and ex- Tiabo valley forms a corridor providing access to the west coast tending southwestward almost to Dodinga Bay, is a belt of low at 2 points (Bakoeloe Bay and Loloda Bay). The upper reaches mountainous country that forms a fairly effective terrain bar- of the river run through low, hilly country where the main rier. The west side of this mountainous area is formed by a hindrance to cross-country travel is the dense forest cover. steep escarpment which rises from 1,500 to 2,000 feet above (e) Northwest Mountain Ridge. At the northern tip of the Lama valley, which in turn separates this region from the the island, a steep mountain ridge rises directly out of the sea volcanic range to the northwest. Only short, swift streams have and trends southwestward to Loloda Bay. Average elevations indented this escarpment. East of the escarpment crest, which along the crest of this ridge are between 1,500 and 2,500 feet. forms the highest part of the area, the land surface is very The only notable break in its continuity lies directly behind the broken, with long, irregular ridges and valleys trending roughly small bay of Bakoeloe, where a low pass at only 300 feet ele- eastward. One of the more important cross-island trails passes vation leads across to the Tiabo valley. The coastal plains on the up the Lamo valley, and leads across a belt of hill country to the eastern side of the ridge are somewhat wider than those on upper Kaoe valley. An area of fairly rough hill country extends the west side, but still are narrow, usually being less than a mile southward from the southern end of the mountain belt to the in width. Dodinga Ischmus. The narrow Dodinga Ischmus itself is easily crossed, as is evidenced by the fact that natives often drag their (4) Morotai Island. boats across it from Dodinga Bay to Bobane Bay in order to The interior of Morotai is mountainous, and, although few avoid the long route around the southern end of the island. On details are available on interior terrain conditions, there appear the northwestern side of Kaoe Bay, extending northeastward to be 2 low mountain ranges trending from southwest to north- from Akelamo, is a coastal plain about 4 miles wide at its east, with a depression between them. The western range, widest point. Except for a narrow beach strip along the shore, maximum elevation 3,333 feet, closely parallels the coast, ris- this area appears to have little military significance because of ing abruptly from rocky headlands or narrow coastal flats. The the extensive swamps that cover most of the plains. eastern ridge (Sabatai Mountains) has a maximum elevation (c) Central Volcanic Range. The central part of the of 4,100 feet, and lies somewhat farther from the coast, being northern peninsula lies along a line of former extensive vol- separated from it by a narrow interior lowland, a belt of low canic activity. This line rrends from northeast to southwest. coastal hills, and a narrow strip of coastal plain. This eastern Along it is a string of volcanic peaks, from Djailolo on the coastal plain, despite its narrowness, contains a relatively dense southeast to the rugged Tobelo Mountains on the south side of native population. Galela Bay. Some of these volcanic peaks exceed 4,000 feet in The largest area of lowland is on the southwestern side of elevation. The sides of the volcanoes are entrenched by numer- the island. An isolated belt of hills divides this lowland into a ous steep-sided ravines. Although the volcanoes do not consti- northern and a southern portion. There are rather extensive tute an unbroken mountain barrier, the entire area is wild and sago swamps on the southwestern plain, particularly back of the rugged. Between the main axis of the volcanic area and the Tiabo narrow, sandy, beach ridges along the west coast. Page 11 4 MILITARY GEOGRAPHY 05 FIGURE Il - 1. Northern Halmabera. Djailolo-Soesoepoe plain, near the road crossing of the Lamo River. 1944. Typical vegetation pattern-scattered clearings and secondary growth. (5) Western Volcanic Islands. and settlement from the earliest days. Flat coastal plains are West of Halmahera is a string of 7 volcanic islands extend- rare, and, where found, are usually swampy, hence unsuited to ing from north to south for a distance of about 50 miles. They airfield development. The majority of the cones are still include, from north to south: Hiri, Ternate, Maitara, Tidore, active, and their flanks are not deeply dissected. Mare, Moti and Makian Islands, They have considerable im- portance from an administrative and commercial standpoint. (6) Batjan Islands. For this reason and because of their location, these islands The Batjan Islands form an important group immediately merit consideration in strategic plans for operations in this sec- southwest of Halmahera. tor, despite the fact that they are little more than ash cones rising (a) Kasiroeta. This island lying west of Barjan Island, out of the sea. The lower slopes of the cones are fairly gentle does not have as rugged a land surface as Batjan (below), al- and concave, and the richness of the soil attracted cultivation though it contains little actually flat land. The steepest slopes MILITARY GEOGRAPHY Page Il 5 face the west coast and are a short distance back of it. A low- B. Sangihe-Talaud Islands. land crosses from west to east between Kasiroeta Bay and Imboe-imboe Bay near the southern end of the island. Much These 2 groups of islands lie between the northeastern tip of the western portion of this lowland is sago swamp. Much of Celebes and the southernmost tip of Mindanao. of the coast of Kasiroeta Island consists of rocky headlands, (1) Sangibe Islands. and coastal plains are limited mostly to small strips at the heads The Sangihe group consists of volcanic cones or groups of of bays or coves. cones, some of which are active. They have little military im- (b) Batjan Island. Batjan, the largest island of this portance, since there are no large sheltered harbors, and flat group, lies southwest of Halmahera, and is divided into 4 sepa- land suitable for airfield construction is notably absent. Coastal rate blocks of rugged mountainous terrain. Separating them plains are narrow and discontinuous, and in the wider portions are 3 lowland areas; the Laboeha plain, the Wajaoea plain, (not exceeding I or 1½ miles) generally are swampy. Sangihe and the Sajoang valley. The first 2 have a large propor- Island is the largest of the group. In a few cases, such as on tion of swamp. The 3 lowlands form corridors across the is- Sangihe and Siaoe, there are good cross-island routes, located in land. Within the mountain blocks, the ridges and valleys have the gaps between the volcanic cones (FIGURE II 2). The is- little alignment with each other, and cross-country travel is lands are made up largely of loose volcanic detritus, although difficult in any direction. The northwestern and southeastern there are several areas of solidified lava and terraces of coral blocks are not quite as rugged as the other two. Maximum ele- limestone. The latter are common along some of the costal vations vary from 2,500 feet to 6,925 feet (Mount Sibela). The lowlands. plains, other than the 3 lowlands mentioned above, border the (2) Talaud Islands. coast and are narrow and discontinuous. The west coast, border- The Talaud group are chiefly of sedimentary origin, hence ing Sambaki Strait, is almost a continuous marshland about 10 differ from the volcanic Sangihe Islands. The Talaud Islands are miles long. considerably lower, the highest elevation, on Karakelong, be- (c) Obit. This island is located between Mandioli and ing 2,222 feet, and common elevations in the interior being Batjan. Most of the central and northeastern parts of the island between 1,000 and 1,500 feet. The bulk of the island masses are hilly with a maximum elevation of 630 feet. There are nar- consists of limestone. Most land surfaces are exceedingly rough row flats along the western and southern coasts. despite the moderate relief. The largest areas of flat plains are (d) Mandioli. Mandioli Island is the third largest in the located along the southeastern coasts of Salebaboe and Kaboe- group and lies south of Kasiroeta. It is hilly in the interior, but roeang. Because of the roughness of the interior portions of the considerably lower in elevation than the 2 larger islands in the islands, there are few good cross-country routes, travel between group. It reaches a maximum of 1,986 feet. A narrow coastal different parts of the same island generally being along good plain about 1/2 mile wide borders most of the coastline. The coastal trails. A good route crosses the central portion of Kara- portion along the south coast is swampy. kelong, however, from Beo on the west coast, to Rainis on the cast coast. (7) Lesser islands. Although there are 120 islands adjacent to Halmahera which C. Mindanao and adjacent islands. exceed 1/2 mile in diameter, the largest of these is only 11 miles (PLAN 1). long. Fewer than 30 exceed 2 miles in length. These islands In contrast to the other larger islands treated in this report, vary considerably in shape, elevation, vegetative cover, coastal Mindanao has relatively large areas in the interior where both characteristics, and military value. relief and vegetation are suited to large scale military opera- FIGURE Il 2. Sangibe Idands. Siace Islands, Hoeloe village, looking W. 1939. A motor road utilizes the pass berween the two volcanoes and leads to Ondong village on the west side of the island. Page Il 6 MILITARY GEOGRAPHY tions, particularly in a north-south direction. There are a num- plateau rises directly from the sea from Linao Bay northwards ber of high mountain ranges, most of which have volcanic to the mouth of the Mindanao-Pulangi River, except for a few peaks rising well above 7,000 feet, but some of these ranges are small bays or coves where there are stream mouths. In general, broken by natural corridors or defiles. There are 3 main corri- the streams in the limestone area have their sources in the range dors across the island from north to south. These are, from west of hills that rise above the plateau near its northern edge. They to east: the isthmus between Illana and Iligan Bays; the Bukid- flow southwestward in narrow, deep ravines. Except for the non Uplands (FIGURE II - 3) with their grassy plains, lying Koronadal valley route, the entire region would be extremely between Macajalar Bay and the Cotabato Basin; and the Agu- difficult to cross. There are a few narrow coastal plains along san Valley, including the low hilly terrain that separates it from the southwestern coast, such as at Linao Bay, Port Lebak, and the lowland at the head of Davao Gulf. This latter corridor is Kling. largely unusable as a route for troop movements because of large areas of swamp and marsh. The most continuous terrain (2) Central Mountain Region. barriers are the mountain ranges that lie to the east and west This long north-south mountain range, extends from the of the Agusan basin, and the belt of rugged terrain that runs the Mount Apo district, which is southwest of Davao, northward to length of Zamboanga Peninsula. The only easy east-west corri- the north coast. It is perhaps the most effective terrain barrier on dor leads northwestward from the west side of Davao Gulf to the island (FIGURE II 5). It is high and rugged throughout its the Cotabato Basin. Routes within the Agusan and Cotabato length and there are no easy routes across it. Routes from east- Basins are restricted, owing to extensive marshes. ern Mindanao to the western portion of the island either skirt The arrangement of the mountains, plateaus and lowlands the northern end of the range, closely following the coast, or permits a logical compartmentation of the island into relief pass through the Cotabato-Davao corridor that separates the regions. These various regions will be described separately in southern end of the range from the Southern Mountain Region. the following paragraphs, beginning in the south and progress- The highest elevations are found in the group of volcanic peaks ing around the island in a counter-clockwise direction. southwest of Davao, of which Mount Apo is the highest (9,690 feet). There has been an appreciable spread of cultivation from the Davao coastal plains up the long lower slopes of the peaks. (3) Davao Lowlands. These lowlands extend northward from Malalag Bay (on the west side of Davao Gulf) around the head of Davao Gulf (FIGURE II 6). The terrain is flat to rolling. The narrowest portion is near the village of Santa Cruz, where the mountain slopes come within a few hundred yards of the coast. Elsewhere the mountains are 3 to 25 miles from the coast. The flat plains are limited to fairly narrow coastal strips and alluvial flats along the lower stream courses. The largest of these are in the Padada-Digos Valley, the area northwest of Daliao, and at the head of Davao Gulf. The most important terrain features are FIGURE II 3. Mindanao. the remnants of old gravel terraces that rise above the general Bukidnon Uplands. Looking WNW toward Pangantocan. 1939. Typi- level in the inter-stream areas and command the plain and sea cal undulating open grassy terrain in southern Bukidnon, approaches. They have been dissected by streams until they appear as low hills. Many of them are cleared for abaca fields (1) Southern Mountain Region. and could be climbed by tracked vehicles; others are steeper This region includes the mountainous district in the south and covered with trees. The belt of gravel terraces becomes central part of the island. Its northeastern boundary is formed much wider toward the head of Davao Gulf and continues al- by the pass that is followed by the Cotabato-Davao highway. most to the Agusan Basin to the north. On the east side of the On the north is the broad Cotabato Basin. The peninsula east gulf, the coastal plains vary considerably in width, and in many of Sarangani Bay is almost entirely mountainous (FIGURE II places the mountain foothills come out to the coast (FIGURE 4). West and northwest of Sarangani Bay, there are 2 rugged II 7). In contrast to conditions on the western side, there is lit- areas of volcanic peaks. Separating these areas is a low corridor tle cultivated land on this side of the gulf. extending from the northwestern corner of Sarangani Bay to the southeastern corner of the Cotabato Basin. This corridor (4) Eastern Mindanao Region. (the Koronadal Valley) has recently been the scene of consid- This region includes all of the easternmost part of Mindanao, erable colonial activity, and is traversed by a highway com- east of the Agusan Basin and the Davao Lowlands, and extends pleted just prior to the war. The mountains continue to the from Bilaa Point on the north to Cape San Agustin on northwest without a break to a point northeast of Linao Bay. the south. It is largely an area of mountainous terrain, with dis- At this point the mountains become lower in elevation and continuous coastal plains bordering the bays. The northern por- continue as a low range of hills to Tapian Point. The entire tion is formed by the Diuata Range. The mountain belt is al- northwestern portion of the region, with the exception of the most a continuous barrier 20 to 40 miles wide, having average range of hills just mentioned, is a dissected plateau of lime- elevations of about 3,800 feet in the north and 2,700 feet in the stone and other sedimentary rocks. Its highest portion (2,000- south. Individual peaks rise to 6,000 and 8,000 feet. The only 2,500 feet) is on the northern and northeastern side, where breaks in its continuity are the Lake Mainit-Surigao corridor there is an abrupt slope down to the Cotabato Basin. This near the northern end. and the Lupon-Mari corridor that cuts .T. Confidential MILITARY GEOGRAPHY Page Il - 7 MALALAG BAY FIGURE II 4. Mindanao, Malalag Bay, Davao Gulf. Looking SE. 1935. Forested mountainous terrain typical of the Southern Mountain Region. FIGURE II 5. Mindanao. Central Mountain Region. Looking SE. Malaybalay village in foreground. 1935. Western front of the Central Mountain Region, at the eastern edge of the Bukidnon Uplands. Page Il 8 MILITARY GEOGRAPHY across the narrow neck of the peninsula east of Davao Gulf. Hinatuan, Lianga, Lanuza, Carrascal, and Becebos. The maxi- West of Hinatuan Bay, the mountain belt is narrow (only mum width of these coastal lowlands is about 7 miles. about 10 miles wide); and this was selected as the best location (5) Agusan Basin. for a road connecting the east coast with the central portion of This large valley extends nearly the entire north-south length the Agusan Basin. There is much limestone that has been of eastern Mindanao. The Agusan River which drains this basin elevated to heights of from 500 to 1,000 feet along the east is 130 miles long. Its source is in the mountain district east of coast. Such areas are difficult to cross because of the rough Davao Gulf. The basin proper begins near Moncayo, at the surfaces, steep-sided ravines, and vertical cliffs facing the sea northern edge of the low hilly zone that separates it from the (FIGURE II 8). Remnants of such plateau areas stand out as lowland at the head of Davao Gulf. From Moncayo northward, isolated hills on many of the coastal plains. The plains border- there is a broad, flat trough all the way to the north coast. There ing the east coast are isolated from each other and from the rest are no broad areas of foothills bordering the plain, and moun- of the island (FIGURE II - 9). The largest of these plains are tains rise abruptly from the plain along much of the eastern found bordering the larger bays, such as Mayo, Cateel, Bislig, side. An important feature of the basin is the marsh and lake MINDANAOL. DAVAO GULF DAVAO FIGURE II 6. Mindanao. Davao Lowlands. Daliao plain. Looking NW from a point about 8 miles NE of Astorga. 1935. Narrow strip of coconut palms near coast. Exten- sive abaca plantations in Sirawan valley in rear. Plantations and second growth woodland in middle distance. Highland border on horizon. MINDANAOL Piso FIGURE II 7. Mindanao, East side of Davao Gulf. Looking NE toward Piso Point. 1935. Mountainous absent. topography, Dense tropical rain forest growth. Coastal lowlands MILITARY GEOGRAPHY Page Il 9 FIGURE Il 8. Mindanao. Entrance to Lamon anchorage. Steep-walled, densely forested coast, typical of east coast peninsulas on Mindanao. district in the central portion. This is a serious barrier to cross- country movement. The highest and best drained portions of the flat plain are along the banks of the river, or along the old banks of abandoned stream channels (FIGURE II - 10). FIGURE Il 10. Mindanao. Agusan Basin. Looking SE over Talacogon village. 1939. Wooded and cultivated areas on slightly higher ground next to river. Marsh grass on lower land farther back from river. (6) Bukidnon Uplands. This region, located in the central part of the island, is char- acterized by wide, sweeping, grass-covered valleys and slopes, surmounted by more or less isolated groups of volcanic moun- rains. The northern end of the uplands lies only a mile or two from the head of Macajalar Bay, and rises abruptly from the narrow coastal plain. On the south, the uplands slope gently southward, merging with the gravel terraces and low hills that border the northern side of the Cotabato Basin. As a rule, the surfaces of the valleys and slopes lie at elevations of between 1,500 and 3,000 feet, and slope away gradually from the groups of mountains. FIGURE Il 9. Mindanao. The largest mountain groups are the Katanglad and Kala- Careel River. 1942. Obstacles to overland travel: steep cliffs, thick vegetation cover, and tungan Mountains (FIGURE Il - 11). There are also a few iso- boulder-strewn river. lated volcanic cones rising above the general level of the up- Page Il 10 MILITARY GEOGRAPHY MARAMAS FIGURE Il 11. Mindanao. Bukidnon Uplands. Looking NW over Maramag village toward southeastern end of Kalatungan Mountains 1935. Typical distribution of grass- lands and forests. land plains, In the northern part of the region, the streams that narrow coastal plain (FIGURE Il - 12). This escarpment is cut radiate outward from the Katanglad Range have cut deep, by innumerable steep-sided ravines. Supporting this defensive steep-sided trenches into the gently sloping deposits of vol- line are flanking positions for secondary defense that can be es- canic material that constitute much of the region. Farther south, tablished along the larger canyon-like trenches that are cut along the middle course of the Pulangi River, the slopes are into the plateau, particularly the trenches of the Cagayan and less dissected, and the country has the appearance of gently un- Tagoloan Rivers and their tributaries (FIGURE II - 13). Near dulating prairies. the headwaters of the Maridagao River there is a pass that gives From a military standpoint, the most important factors in the access southeastward from the Iligan Bay-Lake Lanao district geography of the region are: the numerous airfield sites (many (FIGURE Il - 14), but the dense forest west of the pass would of which require little more than cutting or burning the tough, be a handicap to overland travel there. tall "cogon" grass to make them usable as emergency landing fields); the general suitability of the terrain for large scale mili- (7) Lanao Uplands. tary operations; the central position on the island; and the natu- West of the Bukidnon Uplands, and extending toward the ral approaches from the south and north. narrow isthmus between Iligan and Illana Bays, is an area of The most logical approach from the south is up the Pulangi diverse terrain features. The southeastern part is formed by a River valley, along the Sayre Highway. There are few points range of high volcanic peaks trending almost east-west, includ- where hilly terrain constricts the southern approach, but there ing Mount Piapayungan (9,233 feet), Mount Ragang, and are possible defensive positions near Kibawe. The Maridagao Mount Latukan (7,598 feet). The lower slopes of this range are valley is a poor route of approach from the south because of the long and sweeping, similar to those in the Mount Apo district. rough terrain along much of its lower course. The Central In the northeastern part of the area, extending northwestward Mountain Region forms an effective barrier along the eastern from the Bukidnon Uplands Region, and forming the peninsula side of the Bukidnon Uplands. The mountains rise abruptly between Iligan and Macajalar Bays, is an area of hilly terrain, (FIGURE Il . 5), and only poor foot trails lead across from the not particularly high (average elevation 800 to 2,000 feet). Agusan Basin. but exceedingly rough. The most logical defensive position against approaches from The coastal plain bordering Mindanao Sea is narrow, except the north (Macajalar Bay) is the escarpment that borders the at the head of Panguil Bay (the narrow extension of Iligan MILITARY GEOGRAPHY Page Il 11 FIGURE II 12. Mindanao, Northern edge of Bukidnon Uplands. Looking S from Bugo on Macajalar Bay. 1936. The dissected escarpment seen in the middle distance offers good natural defenses. (See also Figures IV 70 and IV 71). 1958 FIGURE II 14. Mindanao. Bukidnon Uplands. Kidanguin River near its junction with the Mari- dagao. Looking N toward lower slopes of Kalatungan Mountains. 1939. 1648942 The pass berween the upper Maridagao valley and the Lake Lanao area is in the far left rear. FIGURE 11 13. Mindanao. Bukidnon Uplands. Mangima Canyon, at crossing point of Sayre (Ma- (FIGURE II - 15), and continues eastward on the east side of the laybalay-Cagayan) Highway. Looking N toward Tagoloan Canyon. lake toward the pass leading to the Bukidnon Region. 1939. Characteristic gorge-dissected terrain of northern Bukidnon Region. On the west side of the lake, and paralleling it, is the Gurain (Gurayan) Mountain Range. This range swings westward near the southwestern end of the lake, and widens southward as far Bay), where there are great expanses of mangrove swamps. The as the coast of Illana Bay, forming a belt of rough terrain that major part of the region consists of an undulating to rolling blocks land communications between the eastern and northern land surface that rises gradually from Iligan Bay to Lake Lanao portions of Illana Bay. At the western end of the region, there Page Il 12 MILITARY GEOGRAPHY is only a belt of low hills separating the coastal plains at the of Sibuguey Bay. One of the few cross-country routes in the re- heads of Illana and Iligan Bays. This isthmus has considerable gion lies between the lower part of this valley and the small strategic significance because it affords the easiest crossing of port of Malangas, on the west side of Dumanquilas Bay. The Mindanao from south to north. Within the region, there are only good land exit from the region is the coastal road that 3 points toward which land communications focus in the Lanao skirts the north coast. The western terminus of this road is Upland Region. These are the gap between Illana and Iligan Sindangan, on Sindangan Bay. Foot or pack trails afford the Bays (mentioned above); the pass at the southwestern end of only means of cross-country movement across Zamboanga Lake Lanao, berween the southern end of the Gurain Range Peninsula. Movement along routes paralleling the southern and the northwestern end of the volcanic region lying south coast is hindered by hill spurs that form rocky peninsulas, by of the lake (FIGURE II 16); and the gap at the northern end rough coral terraces, and by swampy stream mouths. of Lake Lanao (near Dansalan) between the Gurain Range and the northwestern extension of the Kalatungan Mountains (9) Cotabato Basin. This large lowland covers 1,800 square miles. It opens west- ward to the east side of Moro Gulf. It is approximately 60 miles long, from northwest to southeast, and 30 miles wide (FIGURE II - 19). It is similar to the Agusan Basin in that it contains large areas of poorly drained land, such as the Libungan and Liguasan marshes (FIGURE II - 20), and a dense network of sluggish, winding streams. The northern portion of the region is bordered by a zone of low, gravel and limestone terraces. The eastern portion merges with the long slopes of the volcanoes in the Mount Apo area, and the southern border is formed by the steep northern front of the Southern Mountain Region. At sev- eral places, isolated, low, flat-topped hills of soft limestone rise above the flat surface of the plain, such as the Cotabato airfield, Reina Regente, and Pikit (Fort Pikit). FIGURE II 15. Mindanao. Entrances to the region, except by sea, have already been Lanao Uplands, near Dansalan. Looking NW from north end of treated in the descriptions of adjacent regions. These entrances Lake Lanao, across Saguiaran valley toward Illigan Bay. 1943. Charac- teristic undulating terrain. include: the Koronadal corridor from Sarangani Bay; the pass from the west side of Davao Bay; the Bukidnon Upland (8) Western Mindanao. route via the Pulangi valley; and the Lake Lanao-Illana Bay The western end of Mindanao, including Zamboanga and route, via the Malabang coastal plain and the Balut Lake dis- Misamis Occidental Provinces, is essentially an area of rough trict (FIGURE II - 21). The highways of the area generally mountainous terrain and isolated segments of coastal plains. The greater portion of the rugged terrain lies at elevations of avoid the poorly drained sections, keeping to the slightly higher terraces along the northern side of the basin. Approaches from from 2,000 to 4,000 feet, but Mount Malindang in the center of the seaward side would be hindered by the Distributaries of the Misamis Oriental Province (west of Iligan Bay) rises to 7,956 Mindanao River. feet. The interior of Western Mindanao is difficult of access (FIGURE II - 17), and is little known. The longest and widest (10) Adjacent islands. coastal plains are found at the southern end of Zamboanga There are 88 islands exceeding 1/2 mile in diameter which Peninsula (FIGURE II 18), and along the western side of Ili- are adjacent to Mindanao. They vary greatly in physical char- gan Bay. Even here, however, the width of the plains does not acter and military importance. One of these, Samal Island (FIG- exceed 5 miles. Another fairly large lowland extends up the Sibuguey River for about 20 miles, from the northeastern head URE II - 22), has particular significance because it is large and lies near the head of Davao Gulf and opposite the city of Davao. FIGURE Il 16. Mindanao. Lanao Uplands. Looking S along west side of Lake Lanao, Gurian Mountains to right. Ganassi Peaks in distance to left. The gap between is utilized by the Dansalan-Cotabaro highway. MILITARY GEOGRAPHY Page Il 13 FIGURE Il 17. Mindanao. Zamboanga Province. Looking NW on west side of Dumanquilas Bay. 1931. Typical hilly terrain. Dense forests in interior. D. Sulu Archipelago and Basilan Island. and as a general rule, such travel would not be difficult, as there All of the larger islands in the chain that extends from the are wide areas of open grasslands and cultivated fields. Swampy southwestern tip of Mindanao to norrheastern Borneo are areas would hinder deployment of troops in some of the coastal rugged and forested. Of these, only Jolo and Tapul contain ap- flats such as in the vicinity of the town of Jolo and along the preciable areas of flat to rolling land, with adequate cross-island shores of Tutu and Maimbung Bays. routes for military operations. Many of the smaller islands in (3) Tawitawi Island. the archipelago, however, are low and flat, and appear to have This large island, located. near the southwestern end of the suitable sites for airfield development. Sulu Archipelago, is 32 miles long from southwest to north- (1) Basilan Island. east, and is from 5 to 16 miles wide. Most of the interior is The large island lying south of Zamboanga Peninsula (Min- rough, hilly terrain (FIGURE II - 24). The highest point is danao) is Basilan. It is 35 miles long from east to west, and 23 Mount Sibankat (1,803 feet), There are only a few fairly large miles wide. Most of the interior is hilly to mountainous, the areas of low, level land, such as at the extreme southwestern highest peak, Basilan Peak, rising to an elevation of 3,317 feet. end of the island (FIGURE II 25), and near the northwestern There is a series of mountain peaks encircling the interior of end, between the Dungun River and Kula Kula Channel. The the island 5 or 6 miles inland from the coast. Within this cir- half of the island southeastward from Mount Sibankat is com- cle the terrain is less high, consisting of rolling upland country. posed of sedimentary rocks which have been dissected without a The largest lowland area is along the northern coast in the regular pattern of valleys and ridge lines. The northwestern vicinity of Lamitan, the largest settlement on the island. The half, on the other hand, is composed of a different type of rock, lowland along the southwestern coast is flat and swampy. and there is formed a more or less continuous central ridge, trending northeast-southwest. Several airfield sites are reported (2) Jolo Island. in the small islands that lie off the southwestern part of Tawi- tawi. Jolo Island is 38 miles long from west to east, and 3 to 14 miles wide. Several volcanic peaks and hills rise singly from (4) Lesser islands. gently rising slopes (FIGURE II - 23), The highest and most There are 165 islands in the Sulu Archipelago which have a rugged part of the island is in the west, where more than 10 diameter exceeding 1/2 mile. Most of these are small, but some peaks rise above 1,000 feet elevation, with 6 of these surpassing have potential military value and should be studied in detail. 2,000 feet. Some of these volcanic peaks have craters at their FIGURES II - 26 and II - 27 show characteristic terrain for some summits. Between some of the peaks are wide passes or valleys of the lower islands. followed by roads that serve the island exceptionally well. Most of the useable gaps trend from north to south. Many gullies and E. Northern and Eastern Borneo. ravines dissect the steeper hill slopes. The mountain peaks Few details are known about terrain conditions in the interior and hills are only local barriers to cross-country travel, part of this region. The coastal districts, on the other hand, are Page II 14 MILITARY GEOGRAPHY fairly well known, particularly along the west coast. The in- There are no well-developed cross-island routes. The almost terior consists almost entirely of highlands, most of which are continuous covering of forest, the hilly to mountainous terrain, composed of rough terrain. High mountain ranges do not con- and the lack of settlements in the interior have effectively dis- stitute a large percentage of the land area except in the north- couraged the construction of roads between the eastern and western portion of the region, where a series of ranges, trend- western coasts. Most travel in the interior is either by boat along ing from northeast to southwest forms a barrier to east-west, the larger rivers, or by foot over native trails. The best potential cross-country travel. The highest of these ranges is the Crocker route for cross-island road development leads westward from Range, which culminates in Mount Kinabalu, elevation 13,498 Sandakan to the basin in the upper Sugut valley east of Mount feet (FIGURE II - 28). There are several places in the interior Kinabalu, and joins the Kota Belud-Pegalan valley-Beaufort where stream valleys widen to form flat to rolling, basin-like route at Ranau. depressions, such as in the Pegalan valley southeast of Jessel- Instead of dividing Borneo into terrain regions as was done ton, and along some of the upper tributaries of the Koetai, in the descriptions of Halmahera and Mindanao, only 2 di- Kajan, Sembakoeng, and Sugur Rivers. With the exception of visions (corresponding to the areas under Dutch and British the Pegalan valley, these basins are isolated, and of little mili- control prior to the war) will be described. tary importance. Coastal lowlands are wider along the east coast than on the (1) Dutch Borneo (north of the Equator). west, because the largest rivers in the region flow out to the This part of the region is essentially an area of rough, hilly eastern or northeastern coasts, building extensive alluvial terrain, fringed on the west by a low mountain range, and on plains and deltas near their mouths. A characteristic of nearly the east and south by wide, flat, poorly drained, alluvial plains. all of the coastal areas is the presence of isolated hills or groups The largest area of such river plains is in the southeast, in the of hills that rise steeply from the surrounding lowlands without basin of the Koetai River. Another area of low, marshy any regular pattern of distribution or alignment (FIGURE Il - river plains is found in the multiple deltas of the Kajan, Sesa- 29). jap, and Sembakoeng Rivers. The Sangkoelirang and Beraoe FIGURE II 18. Mindanao. Zambounga coastal plain, looking NW from Caldera Bay, 8 miles west of Zamboanga. 1925. Cultivated lowlands, forested highland interior. MILITARY GEOGRAPHY Page Il 15 LANDING FIELD PIKIT, COTABATO, MINDANAQ P.I. FIGURE II 19. Mindanão. Cotabato Basin. Looking NW from Pikit toward highlands at basin edge. 1935. Rivers also have broad lowlands near their mouths. A large the coastal lowlands become narrower toward the north, and portion of the interior consists of dissected plateau country. are displaced entirely by hilly terrain in several places north of Stream valleys are deep and narrow. The underlying rock is Tuaran. The Crocker Range forms almost a continuous wall principally sedimentary, including much sandstone. Cross-coun- facing the west coast, about 10-15 miles inland. It is broken by try travel is hindered more by stream gorges and dense vegeta- only one major pass-the gorge of the Padas River, southeast tion than by mountain barriers. The highest chain is the Muller of Beaufort. Another pass that is much more difficult is located Range, between 3,000 and 4,000 feet in elevation, which forms along the southwestern flanks of Mount Kinabalu, and connects the extreme southwestern corner of the region. The northern the Ranau plain with the upper Tempasuk River that flows extension of this range, the Iran Mountains, is lower. Still far- out to the west coast northwest of Kota Belud. Northeast of ther north, the mountains increase in elevation, and the range Mount Kinabalu, the Crocker Range divides, one branch extend- splits into several off-shoots which form the rugged mountain ing north and forming the mountainous backbone of the penin- chains of British North Borneo. If it were necessary, potential sula west of Marudu Bay, and the other bending eastward to be routes for motor roads could undoubtedly be found that would joined by other ranges from the south. connect Dutch East Borneo with Sarawak, Brunei, or British The largest interior depression is the Pegalan valley that North Borneo. To develop any such routes, however, would re- forms a trough from northeast to southwest on the east side of quire an immense amount of labor, primarily in clearing the the Crocker Range. It varies in width, but at 2 points (near forest, grading and filling, and constructing bridges. Keningau and Tambunan) it is a flat, grassy basin several miles in width. The exit southward from this valley is via the Padas (2) British North Borneo. gorge, and that northward is over a fairly low divide into the This part of Borneo is much more rugged than the Dutch Ranau plain, a partially dissected plateau lying east of the base portion previously described. Along the west coast is a lowland of Mount Kinabalu. that is widest in the delta area of the Padas River. Hills that East of the major drainage divide, in northern Borneo, the rise steeply from the plain are scattered near the coast, but are general features of the terrain are similar to those in the Dutch grouped into a belt of foothills a few miles inland. In general, territory farther south. The drainage basins are larger than those Page Il 16 MILITARY GEOGRAPHY 27613 A.O FIGURE II 20. Mindanao. Cotabato Basin. Liguasan Marsh, showing floating islands. 1936. FIGURE Il 21. Mindanao. Cotabato Basin. Looking NE toward Lanao Uplands 1939. Typical terrain in the Balut Lake district along the route from the Malabang coastal plain to the Corobato Basin. west of the divide, the streams are larger, there are broad hindered by the swamp and marsh lands and also by the belts swampy areas near the river mouths, and there is less mountain- of heavily forested hills that occasionally rise above the low- ous terrain. Land travel parallel to the coast would be greatly lands in the inter-stream areas. MILITARY GEOGRAPHY Page Il 17 579 SAMALL PENAPLATH FIGURE II 22. Mindanao. Davao Gulf. Samal Island, looking N toward head of gulf. 1935. Characteristic terrain on west side of island. (See also Chapter IV, Topic 43, R). FIGURE II 23. Sulu Archipelago. Jolo Island. Looking W. 1936. Typical terrain in vicinity of Seit. Page Il 18 MILITARY GEOGRAPHY TAWI TAMI I FIGURE II - 24. Swin Archipelago. Tawitawi Island. Looking S. 1937. Hilly terrain typical of most sections of the high islands in southern portion of the Sulu Archipelago. FIGURE II - 25. Sulu Archipelago, Tawitawi Island. Looking SW at southwestern corner. 1935. One of the few possible airfield sites on the island. MILITARY GEOGRAPHY Page Il 19 FIGURE Il 26. Sulu Archipelago, Western shore of Tapul Island. Looking NE 1935. Cultivated terrain typical of lowlands of islands of the Tapal group. (3) Adjacent islands. For purposes of more detailed description, Northern There are 72 islands whose maximum diameter exceeds 1/2 Celebes has been sub-divided into two regions: an eastern re- mile which are adjacent to Northern and Eastern Borneo. These gion including the Minahasa and Bolaing-Mongondow Prov- differ greatly in physical character and military value, but inces, and a western region, hereafter called the Northern should be studied in detail. Tarakan Island is discussed und.r Peninsula, including all of the peninsula west of the Ongkag- topic 26, Critical Areas. Doemoga River. F. Northern Celebes and adjacent islands. (1) Minabasa-Bolaäng-Mongondow Region. Except for the extreme northeastern or Minahasa end of From a military point of view, this region is much more sig- Celebes, the area north of the Equator has a comparatively sim- nificant than the rest of Northern Celebes. This is because of ple framework of relief. In the interior is a central mountain the availability of several cross-island routes and a fair network backbone, which in a few places sends out tributary spurs of motor roads, the presence of several well-drained, cleared "en echelon" to the coast. The mountains comprise an unbroken areas of flat land suitable for airfields, and a comparatively rampart between the Celebes Sea and the Gulf of Tomini, ex- numerous native population. cept near Gorontalo and in the Minahasa Region. There are 2 main corridors across the island: the Belang- The coastal plains for the most part are narrow, although Amoerang passage on the west, and the Manado-Kema valley fairly continuous. Not all coastal lowlands of Northern Celebes farther east. Of these, the latter is by far the easier, the highest are universally favorable for military operations. This is due to point on the route being only 764 feet in elevation. The former swampy terrain which commonly is found immediately behind the sandy beach ridges and near the mouths of the larger requires an ascent of about 1,200 feet to the plateau level. Con- streams. necting these two routes is a lateral corridor, the Tondano In the Minahasa Region, the relief pattern is quite different. plateau, which includes the flat terrain in the vicinity of Lake Here are found broad, upland flats and rolling country, sur- Tondano. Routes connecting the interior basins and plateaus mounted by several tall, volcanic cones. The approaches to these with the coast are more frequent along the northwest coast upland areas, particularly those from the southwest, are re- than the southeast coast. A possible route from the west into the stricted because of the deep, gorge-like valleys that cut into the interior is from Gorontalo eastward up the Bone valley thence plateau edge. across a hilly divide to the plateau country near the headwaters Page II 20 MILITARY GEOGRAPHY 27649 FIGURE Il 27. Sulu Archipelago. Tawitawi Group. Simunul Island, looking E. 1935. Terrain and vegetarion typical of the low islands in the Tawitawi group. FIGURE Il - 28. British North Borneo. Mount Kinabalu ( elevation 13,498 feet). Direction and date of view unknown. MILITARY GEOGRAPHY Page Il 21 FIGURE II 29. British North Borneo. Northwestern coast. View near Jesselton. Direction and date unknown. Characteristic lowland scene during the wet season. Isolated hills rise above the plain. of the Ongkag-Doemoga River. A military road was planned island route leads northward from Gorontalo to Koeandang, along this route, but was never completed. This route would and a discontinuous interior basin, consisting of the Bone River, join with the main entrance to the Mongondow country (the Lake Limboto, and Pagoejaman valleys, trends roughly east- Lombagin-Kotamobagoe-Doemoga-kerjl road). west (FIGURE II - 31). The lowlands are situated along the The coastal plains on the northwest are wider than those coast, and while fairly continuous laterally, they do not pene- on the southeast. Included among those on the northwestern trate far into the interior. The mountain backbone is almost coast are the Amoerang and Manado lowlands, which extend in- uniform in its sharpness and in its elevation (generally be- land for about 3 miles up the Ranorapo and Manado Rivers re- tween 6,000 and 7,000 feet). It is an effective barrier to cross- spectively. The plateau surfaces become smaller and more iso- country travel, and only in a few places is it crossed by native lated toward the southwest, in the Mongondow area. The largest foot trails. For the most part, it is a single ridge, although in a is in the vicinity of Kotamobagoe. The region has many volcanic few places it is bent, broken, and paralleled by one or more peaks. These rise to elevations considerably greater than those accessory ridges. of the plateaus, lowlands, and corridors which they dominate. The coastal plains along the southern side of the peninsula, The highest volcanoes are Kalabat (6,590 feet), flanking the facing the Gulf of Tomini, are more nearly continuous than northeast side of the Manado-Kema corridor (FIGURE II 30); the plains along the north coast, where there are a number of Lokon (5,210 feet), lying southwest of Manado; and Soepoe- high rugged peninsulas. The head of the Gulf of Tomini is bor- tan (6,000 feet), southwest of Lake Tondano. dered by a continuous coastal plain never more than about 1/2 Cross-country operations in the interior of the region would mile wide. The widest coastal plains along the south coast from not be particularly difficult. The main obstacles would be the west to east are the Oja-Ongka plain, the Bolano-Moöetong narrow ravines cut into the flanks of the volcanic peaks. Be- plain, and the Marisa plain. These plains average about 8 to 10 tween the ravines, the land surface usually is gently rolling, miles in width. with many open, cultivated fields and tree plantations. Wet rice On the opposite side of the peninsula, the principal coastal paddies (sawabs) are found mainly on the flats surrounding plains form a series from the Bay of Tamboe (Bocht van Tam- Tondano Lake. boe) on the southwest, to Lombagin on the east in the follow- ing order: (2) Northern Peninsula. The western portion of northern Celebes differs from the 1. Pambero plain, 5. Kampoeng Baroe (or Tolitoli) northeastern tip of the peninsula in that it is generally lacking 2. Moente-Siboa plain, plain, 3. Lendjoe-Pepe plain, 6. Boeal-Matinan plain, in interior plateaus, basins, and cross-island corridors. An ex- 4. Maradja River lowland, 7. Paleleh plain, and ception to this is in the Gorontalo district where a good cross- 8. Koeandang plain. Page 11 22 MILITARY GEOGRAPHY FIGURE II 30. Celebes. Minahasa Region. Mount Kalabat, Looking E from Manado-Tomobon Road. 1937. FIGURE Il 31. Celebes. Northern Peninsula. Lake Limboro, near Gorontalo. Date and direction of view unknown. Low marshy shores in foreground. Highlands back of opposite shores. MILITARY GEOGRAPHY Page Il 23 These coastal lowlands would not be suitable for the deploy- 22. Drainage and Water Supply ment of mechanized forces except locally, because of swamps, and it is doubtful if there are many places suitable for airfield The drainage and water supply of each of the major sectors of the Celebes Sea Area are discussed individually in the fol- development. Exits from the plains are only lateral (parallel to lowing paragraphs. the coast), and none of them provides access to the strategic Minahasa Region at the northeastern end of the peninsula. A. Halmahera and adjacent islands. The only district that appears to have strategic importance Drainage conditions in many parts of Halmahera are un- from a terrain standpoint is the Gorontalo district. Here is a favorable for military operations, but water supply is generally lowland, the Limboto plain, lying inland from the coast, with adequate for large forces. one narrow gap in the coastal range as its only southern ap- (1) Rivers. proach (FIGURE II . 32). A pass leading from Limboto plain The rivers in Halmahera, without exception, are navigable northward across the peninsula to Koeandang has a maximum only for native canoes (praboes). Sandbars block the mouths of elevation of only 1,384 feet, and a potential route leads east- rivers preventing the entry of larger craft. Most of the streams ward, via the upper Bone valley, to the Bolaäng-Mongondow are short and swift. Almost all are fordable, however, except plateau with its road connections to the Minahasa Region. after heavy rains. The largest stream on the island is the Kaoe River, and it is the only one which is navigable by large prahoes (3) Adjacent islands. of 3 to 4 foot draft for any considerable distance. The sandbar at the mouth of Kaoe River is awash at low tide. This river is a There are 29 islands a mile or more in diameter which are barrier to military advance. Other streams that would be minor adjacent to Northern Celebes. The largest island is 12 miles barriers to cross-country travel in their lower courses are the long. Most of the islands are less than 2 miles long. Some of Tiabo (north of Galela), the Mede (between Galela and To- these islands have military significance in that they flank the belo), the Akelamo (near the end of the northeast peninsula), approaches to critical areas in Northern Celebes. the Sangadji (on the southwest side of Boeli Bay), the Lamo FIGURE II 32. Celebes. Northern Peninsula. Looking N. and inland through gap in coastal range toward Gorontalo and east-west valley. Page II 24 MILITARY GEOGRAPHY (on the Soesoepoe Plain), and the Iboe (mid-way on the west sufficiently large to be an obstacle to overland travel. There are coast of the northern peninsula). no lakes of sufficient size to be of any military significance. There are a few small swamps located on the flat coastal plains, (2) Lakes. particularly near the mouths of the small valleys. They are The only lake of any significance on Halmahera is Galela not of sufficient size, however, to be effective barriers. Although Lake, located several miles inland from the head of Galela Bay. little accurate information is available, it appears that water It is about 2.6 miles long from east to west, and about 1 mile supply would not present serious problems, except for unusually at its greatest width. It is reported to be suitable for a seaplane large military operations. Since there are no rivers or streams anchorage. with a permanent flow, the normal fresh water supply is ob- tained from wells. (3) Swamps. Swamps and marshes constitute one of the greatest obstacles C. Mindanao and adjacent islands. to military operations on the island. Their most common loca- tion is near the mouths of the larger streams and paralleling the In addition to the text material following, a great deal of in- shoreline behind the beaches, although in a few cases they may formation about drainage and water supply will be found in continue for several miles inland along the stream courses. The the regional relief descriptions in Topic 21. swamps are poorly drained areas that are periodically flooded by fairly shallow water and tend to have a forest vegetation, (1) Rivers. while the grassy marsh areas develop where there is deeper Despite the large size of Mindanao, there are only 2 rivers flooding. As a general rule, the marshes are even more difficult that can be used for water transportation. These are the Agusan to cross on foot than the dense palm forests of the swamps. and Mindanao-Pulangi Rivers. Mangrove swamps are commonly found along the muddy (4) Agusan River. This river has the following depths at shores of sheltered bays, such as in Loloda, Djailolo and Dodin- its western entrance: 9 to 10 feet at low water, 12 to 14 feet at ga bays, and at river mouths. Listed below are the largest areas high water over the bar. Above Butuan, it is usually navigable of poorly drained land on the island, given by terrain regions. for about 12 miles by vessels of 8-foot draft or less. At this point (No distinction is made between swamps and marshes.) there is a rocky obstruction over which boats of 6-foot draft can pass. The river is navigable in all seasons by boats of 5-foot (a) Southern Halmabe- (c) Northern Halmabe- draft as far as Esperanza, and in all but the driest weather as Fd. fd. far as Lake Lumao, almost 60 miles from the mouth. In the East coast East coast Northwest of Foja Northeast of Akelamo on wet season, launches with a 5-foot draft may go upstream as Northwest of Weda the norchwest side of far as Bunawan and Veruela. While the Agusan is fairly deep Along the lower course of Kaoe Bay and wide (from 400 to 800 feet), the channels constantly the Kobe River Middle portion of Kaoe shift, and it is advisable to use local guides wherever possible. West coast River Valley The entire river basin, for 15 to 20 miles on either side of the North of Lifofa North of Galela West and northwese of West coast river, is low and traversed by a network of interlocking water Pajaheislam East side of Loloda Bay courses. The highest ground is found along the stream banks. (b) Central Halmabera. South of the mouth of the (b) Mindanao-Pulangi River. The bar at the mouth of Iboe River East coast the Cotabato entrance to the Mindanao River has only about 5 Central portion of the south The head of Djailolo Bay feet of water over it at low tide. The south entrance is used only coast of Boeli Bay The north side of Dodinga The lower portion of the Bay by small native craft. The lower part of the river is navigable (d) Morotai. to launches of 5. to 7-foot draft as far as Paidu-Pulangi at low Sangadji River valley South side of Kaoe Bay Southeast of Wajaboela on the water, and to Pikit at high water. Small launches can go up to West coast west coast. Kabacan at low water, and to the Lumatan River at high water. Berween Cape Dobegasi (e) Batjan Island. There are only a few stretches of firm ground along the lower and Akelamo East of Laboeha course of the river for good boat or barge landings or for bridge Along the mainland coast East side of Sambaki Strait on approaches. The current is fairly strong. The lower valley is opposite the Woda Is- the west coast. covered largely by rice paddies (FIGURE II 33), and the num- lands erous water courses that form a network over the valley floor (4) Water supply. would be a handicap to military operations. Nowhere in the area, does the difficulty of obtaining drinking (c) Other rivers. The other rivers are not navigable by water arise. Nearly all villages obtain their drinking water from river launches except for very short distances (usually less than wells, generally only sufficient for village requirements. The 2 miles) near their mouths. As a general rule, they are obstacles water supply can be increased in any locality by digging addi- to movement only on the flat, narrow coastal plains, where they tional wells, or by utilizing the water in streams. Inland, moun- commonly have tidal characteristics, or in the mountains, where tain streams are available everywhere. It is advisable, however, they become raging torrents following heavy rains. to boil or treat all drinking water to remove possible con- (2) Lakes. tamination. There are many large lakes on Mindanao, but most of them B. Sangihe-Talaud Islands. are located in the marsh and swamp country in the Agusan and Cotabato Basins, and have poor shores or are difficult of access. These islands are well drained for the most part. Lake Mainit south of Surigao, and Lake Lanao, northeast of There are no navigable rivers, and none of the streams is Illana Bay, however, have potentialities as seaplane anchorages. MILITARY GEOGRAPHY Page Il 25 D. Sulu Archipelago. None of the streams of this group of islands is large enough to be of any value for water transportation. A few have swampy tidal estuaries that would be troublesome to cross-country move- ments. There are no lakes of military importance in the archi- pelago. There are 2 general locations for swamps on these is- lands. One location is along low, muddy, sheltered coasts, where mangrove is almost universally present. The other location is along the lower courses of the streams, where they cross flat coastal plains. Fresh water is difficult to obtain in the Sulu Archipelago, es- pecially from December to May. No difficulty will be encoun- tered on Basilan or Jolo Islands, but elsewhere water is at a premium, since there are few permanent streams, springs, wells, or other all-year sources, Shallow wells are dug, from which limited quantities of brackish water are obtained, and cisterns for collecting rainwater are fairly common. If traveling south through the archipelago, large supplies of fresh water should be stocked at Jolo and Siasi in preparation for water shortages farther south. During the dry months, water is the chief concern of the native population in many parts of the southern islands, FIGURE II 33. Mindanao, and they are reluctant to give or sell water. Western Cotabato Basin. Flooded rice fields. Looking NE from a point a few miles east of Cotobato. 1939. E. Borneo and adjacent islands. (a) Lake Mainit. This egg-shaped lake is about 15 miles Drainage conditions are of primary military significance in long from north to south, and 4 to 9 miles wide, the widest por- many parts of Borneo. tion being near the northern end. It is relatively clear of obstruc- (1) Rivers. tions, and there are several sections of shoreline suitable for beaching seaplanes. Within the portion of Borneo treated in this study, there is a great contrast between the rivers that flow toward the west (b) Lake Lanao, This is the largest lake on the island, and coast and those flowing toward the east coast. The former are is located on the Lanao Plateau at an elevation of 2,297 feet. It commonly short and swift, and are of use for water transporta- is clear and deep. Its use by seaplanes is handicapped mainly by tion only for short distances. The main exception is the Padas the frequent squalls which arise suddenly, particularly in the River, which is navigable by large launches for a considerable late afternoon. distance inland. In their lowest courses, where they lie on flat (3) Swamps. coastal plains (FIGURE Il 29), the west-flowing rivers may The 2 great swamp and marsh areas of the Cotabato and often be unfordable during the wet season, thus hindering over- Agusan Basins already have been mentioned under the descrip- land travel laterally along the coast. The rivers flowing toward tion of terrain. They are significant barriers to any cross-country the east are large, and form the main routes of access into the troop movement at any season of the year. They contain innu- interior. They are also major barriers to overland travel at merable interlocking watercourses, lakes, and ponds. The coast- right angles to their courses, since fords and good bridge sites al plains on the island all contain some more or less poorly are rare, particularly along the lower courses. In their lower drained land, the amount being roughly proportional to the ex- reaches these rivers wind back and forth across flat, periodically tent of the flat land. The larger areas of coastal plain swamps flooded river plains. Usually there is a chaotic maze of drainage are at the head of Davao Gulf; near the mouth of the Agusan channels ("pintasans" or "antasans") and abandoned river River; at the head of Panguil Bay (the innermost section of Ili- bends that have ponded water ("danaus") in them on these gan Bay); at the extreme southeastern tip of Zamboanga Penin- plains. Winding ridges of slightly higher ground border the sula; and at the mouths of streams flowing into Sibuguey and present main river channels, as well as the sites of previous river Dumanquilas Bays. courses. The river bottom along the lower reach is almost al- ways muddy. On the Beraoe River (the lower Kelai and Segah (4) Water supply. Rivers) the first firm gravel bank in the stream is not reached There is no problem of an adequate fresh water supply in until 50 miles above Redeb Point. Mindanao. Streams, lakes, springs, and wells could supply an General statements as to the navigability of these rivers can unlimited number of troops. The only possible exception to this be misleading. Some of the reasons for this are: condition is in some of the porous limestone areas, such as be- Wide fluctuations in volume. A difference in depth of 33 feer tween Linao Bay and the Cotabato Basin, and on some of the has been observed at one point, and a rise of 16 feet in a single adjacent islands. These areas, however, are small. A large por- hour was recorded on one of the mountain streams in the central tion of the domestic drinking water on Mindanao is obrained by part of the island. collecting rain water. This is not because of a lack of fresh Changing stream courses. A deep channel may be partially filled, split, or shifted in a short period of time. water, but rather to avoid contamination. All surface and ground Temporary obstructions, particularly log jams-owing to the water should be boiled or treated chemically before being used common practice of dumping trees into the rivers following clear- for drinking purposes. ing for cultivation. Page Il 26 MILITARY GEOGRAPHY Sections with falls or rapids. Many of the rivers have narrow (3) Swamps. gorges along their middle courses, yet have long stretches of Swamps and marshes are found on nearly all of the coastal navigable water farther upstream. Use of rivers by large ocean going vessels is hindered by bars at the river mouths, but several plains, especially near the mouths of streams. Most of the fresh rivers, such as the Kinabatangan, Sesajab, Kajan, Beraoe, and Maha- water swamps contain much sago. The swamps are difficult to kam, have been entered by vessels having less than 15-foor draft. cross on foot, particularly during the wet season. The coastal trails usually keep inland away from the swamps, or follow the (2) Lakes. narrow sandy beaches. There are no lakes of any military significance in this portion of Borneo. (4) Water supply. The supply of fresh water throughout the region is adequate (3) Swamps. for normal military requirements. Swamps and marshes are a common feature of the terrain on the broad, flooded, river plains. They include both forested swamps and grassy marshes, depending on the depth of flooding. 23. Soil Trafficability Although found along the lower courses of all of the larger (FIGURE II 44). rivers, the swamps are most extensive, and are very significant terrain barriers in three broad areas: Soil trafficability refers to the capacity of soil to support the The Mahakam basin (the northern portion of which lies north movement of military vehicles. It refers especially to cross- of the equator and within the boundaries of this study). country movement of vehicles and to traffic on unimproved The multiple-delta region berween the mouths of the Kajan and roads made of local soil, rather than to traffic on improved or Sesajab Rivers. surfaced roads. The area between the Kinabatangan River and Sandakan Bay. (4) Water supply. A. General factors affecting soil trafficability. There is no lack of fresh water in any portion of the main The difference in trafficability between the coarse-, medium-, island, owing to the heavy rainfall and numerous rivers and and fine-textured soils is not as great in the Celebes Sea Area as springs. Some of the smaller islands, however, particularly the in higher latitudes. This results from the type of weathering low coral islands to the northeast, have a water supply problem. (lateritic) which is characteristic of the area and which gener- ally produces medium-, and fine-textured soils which are friable F. Celebes and adjacent islands. and allow excess precipitation to drain rapidly. In spite of this, the general soil trafficability is moderately unfavorable. Drainage conditions are diverse in Celebes but water supply Whenever seasons are referred to in this section, they are is adequate almost everywhere. those of the Northern Hemisphere, in keeping with the treat- ment of climate and meteorology in Chapter V. (1) Rivers.- The frequent rainfall is cumulative in its adverse effect upon There are no large rivers in Northern Celebès. A few streams trafficability since there is little time for the soil to dry thor- are navigable to small boats of shallow draft (3 to 4 feet) but oughly between rains. The rainfall is also generally heaviest in only for short distances. The rivers of Celebes usually have the afternoon or evening, and this tends to prolong further the characteristics typical of mountain streams along most of their nontrafficable period, since much of the time between rains courses, but where they cross the narrow coastal plains they are occurs at night or in the morning when there are unfavorable generally unfordable and wind across swampy flats. conditions for the soil to dry. The weather factors are generally unfavorable to the move- (2) Lakes. ment of vehicles, and largely offset the generally favorable drain- There are several lakes in Northern Celebes, only 2 of which age properties of the soils. Furthermore, the larger islands have appear to be suitable for possible seaplane anchorages. The heavily forested mountain regions in their interiors, which re- largest is Lake Tondano, which has a greatest length of 7% strict movement to discontinuous coastal plains separated by miles, and a maximum width of 31/4 miles. It lies on the Ton- rocky headlands and swampy areas, Many of the smaller islands dano plateau, in the central portion of the Minahasa Region at have steep, rocky slopes or, where they are of low elevation, an elevation of 2,269 feet. Mountains lie near the northwestern have a heavy mangrove cover. The most favorable soils for and southeastern sides of the lake, but there are clear approaches trafficability are those developed on coral atolls, coral islands, by air from either the northeast or southwest end of the lake. and uplifted coral rock along the coasts of the larger islands. Lake Danau also appears to be large enough for a seaplane These soils are generally trafficable at all times. landing, but it is almost surrounded by high volcanic peaks. It No soil surveys of any extent have been made in this area. is 31'o miles long and 1 mile wide. The lake is located in However, written descriptions and geologic information have Bolaing-Mongondow Province, and is the source of the Poigar been used to map the general soil trafficability where possible. River. Since geologic and topographic information is, itself, incom- A third lake, Limboto, is located just west of the town of plete, the soil trafficability boundaries are approximations. With Gorontalo. It has the shape of a rough rectangle, is about 7 these considerations understood, the accompanying map (FIG- miles long from east to west, and 4 miles wide. It is very shal- URE II 44) and the general areal descriptions following low, however, and may be dangerous for float plane use. It is should be of use in determining routes of movement, and soil bordered by considerable stretches of marshy ground (FIGURE trafficability conditions to be encountered over chosen routes II 31). under different weather conditions. MILITARY GEOGRAPHY Page Il 27 B. Soil trafficability in Halmahera. C. Sangibe-Talaud Islands. On Halmahera and some of the larger islands, such as Moro- Almost all of the islands of this area have coarse- and me- tai, Batjan, Mandioli, Kasiroeta, Latalata, and Kajoa, coarse- textured soils occur in rather narrow, discontinuous coastal dium-textured soils developed from volcanic ash and lava. strips. They are derived from layers of conglomerate, volcanic These soils are trafficable except during and immediately after ash, uplifted limestone, clay, and marl, interbedded in vary- heavy rainfall. Some of the islands such as Siace and Sangihe ing combinations. These soils are trafficable except when flood- have active volcanoes. Most of the islands have rugged topog. ed by very heavy rains. Access to them is made difficult in many raphy and steep coastal cliffs, but the larger islands such as places, however, by mangrove swamps. On some of the smaller Sangihe, Karakelong, Salebaboe, and Kaboeroeang have some islands, such as those of the Widi group off the southeast coast low coastal areas, parts of which are swampy and always non- of Halmahera, the coarse-textured soils are derived entirely trafficable. Marie Islet in the Kawio group is low and sandy and from uplifted coral rock, drain very rapidly, and should be should be trafficable at all times. Average rainfall in these trafficable at all times. islands is about 135 inches and shows no significant seasonal The most common soils in the Halmahera group of islands variation, so that throughout the year there will be periods of nontrafficable conditions. are those which range in texture from coarse to medium. They include sandy loams, stony loams, and loams. These are de- D. Mindanao. veloped from a variety of rock types, including old consolidated volcanic debris, more recent volcanic flows and ejected vol- Because of lack of complete information on the soils and canic debris, sandstone, conglomerate, coarse- and medium- geology of this area, the trafficability map has been adapted textured alluvium, schists, and granite. They extend entirely from Pendleton's agricultural topography map. This divides across the islands in some places, such as the northern peninsula the area into convenient units, based on topography and land of Halmahera, and the southern peninsula of Halmahera in the use, which also reflect to a useful degree the type of soil and vicinity of Weda; also on Ternate, Tidore, Moti, Makian, Gebe, trafficability. Gag, and Kofiau. At other places in the islands these soils are The low plains and gentle slopes of hills, not more than separated from the coast soils which are usually coarse-textured, several hundred feet above sea level, have mostly arable, well- as in southeastern Morotai and on Kasiroeta, Batjan and Man- drained soils except in marsh and swamp districts. Most land of dioli. Taken as a group, these soils should be trafficable except this type occurs along low parts of the coast and marginal strips during and immediately following heavy precipitation. How- of the main river valleys. The soils are in large part developed ever, where they occur in heavily forested mountain regions, from poorly consolidated alluvial and littoral sedimentary de- their trafficability will be very poor regardless of weather. posits, tertiary sediments, and both extrusive and intrusive Fine-textured soils also cover large areas on Morotai and Hal- igneous rocks. The soils developed are mostly trafficable except mahera. These include silty clay loams, clay loams, and clays that during and immediately after heavy rainfall. are developed from dark-colored igneous rocks, limestone, marl, Another group of readily trafficable soils consists of those and fine-textured alluvium. These soils are friable; although developed on high land with gently sloping areas large enough slippery when wet, they recover rapidly from the effects of pre- for extensive cultivation. Usually these are friable and well- cipitation. They may be considered somewhat less trafficable drained clay soils from unconsolidated volcanic debris, although than the coarse- and medium-textured soils, These soils also some alluvial soils are included. They are mostly trafficable ex- occur in mountainous regions where unfavorable topography cept during and immediately after heavy precipitation. The restricts ground movement. gentle slopes on which they occur are those flanking large Intermittently flooded soils occur at many places along the volcanic peaks. Movement is relatively unhindered parallel to coasts of the islands, usually at the mouths of streams and rivers. the slopes, but since there are numerous deep ravines and val- These soils are alluvial types and are frequently flooded and leys radiating from the peaks, continuous movement at right nontrafficable during and after rainy periods. During dry angles to the slopes is practically impossible. weather, however, they are moderately trafficable. The most common type of land in Mindanao is rough land The swamps and marshes in the Halmahera group do not at intermediate altitudes. The soils in these areas are thin, well- usually cover large areas in the interior. The larger ones, which drained, and trafficable where topography permits except dur- are on Halmahera itself, have been mapped and should be con- ing and immediately after heavy rainfall. They are developed on sidered nontrafficable at all times unless ground reconnaissance a variety of rocks including poorly consolidated alluvial and lit- reveals feasible routes not now noted on available maps. There toral deposits, recent unconsolidated volcanic debris, tertiary are fairly large areas of swamps and marshland on many of the sediments, and older lavas and intrusive rocks. These soils ex- coastal lowlands and along the larger river valleys. The swamps tend from high mountain areas to the coast in many parts of the (moeras) are very wet and muddy with standing water. Locally islands. Topography is a more serious obstacle to movement over in such areas, a man may sink to his shoulders. The marshland this type of land than soil or weather conditions, except in the (drasland) is also muddy but less deep, and generally there is valleys. no standing water. No attempt has been made to map the nar- Land having periodically unfavorable trafficability is that row coastal mangrove swamps. These are serious obstacles to shown on the map as low rice land or periodically flooded land. landing operations at many places (Chapter IV and accompany- Such areas are confined to the valleys of the Agusan and Min- ing Plans). danao Rivers, to those valleys entering Davao Gulf from the The most favorable season for ground movement is fall, north, and to a small area near Zamboanga. This type of land while the least favorable is spring. Trafficability should gener- is usually found between the permanent swamp and marsh ally be better on the southeastern coasts of the larger, islands areas of the central part of the valleys and the better-drained throughout the area, especially during the summer and fall. land on the lower hill slopes. Where cultivated, these lands are Page Il 28 MILITARY GEOGRAPHY usually flooded and nontrafficable from September through De- Cagayan Sulu. The soils from both the sediments and volcanics cember in the northeastern part of Mindanao, and from Febru- are similarly trafficable where topography permits, except dur- ary through May in southeastern Mindanao. At other times, ing and immediately following heavy rainfall. Steep slopes and these soils are trafficable when dry, but require a longer time to narrow valleys restrict movement of vehicles in many of the regain trafficability after periods of rain than the soil types al- islands on which these soils occur. ready mentioned. The third type of soil is that which occurs in permanently High mountain land is common in the interior of Mindanao nontrafficable swamp and marsh areas. The largest of these areas and in the central parts of its peninsulas. The rugged topog- are indicated on the map. The narrow mangrove coastal strips raphy and dense forests in most of these areas are the chief have not been mapped in all cases but are very common especial- hindrances to vehicular movement. ly around the small low coral islands. The swamp and marsh lands of permanent poor trafficability The average annual rainfall in the Sulu Archipelago is about on Mindanao cover large areas, in the upper Mindanao and 70 inches and on Cagayan Sulu, 83 inches. In the Sulu Archi- Agusan River valleys, where they usually surround the numer- pelgo, the most favorable time for vehicular movement is win- ous lakes. In addition, there are some smaller areas of swamps ter, but conditions become steadily unfavorable as the seasons and marshes along the coasts of Mindanao and the smaller progress into summer. On Cagayan Sulu trafficability conditions islands off its shores. Since steep slopes extend to the shores at are best during spring and least favorable during fall and win- many places on Mindanao, coastal shallow water and mangrove ter, which reflects the island's exposed position to the northeast swamps are limited except in some of the bays. The more im- monsoons. portant coastal obstacles are discussed and mapped in CHAPTER IV. F. Northern Borneo. There is considerable variation in annual rainfall and its Soil trafficability information of only general nature is avail- seasonal distribution in northern Mindanao. The most favorable able for Northeast Borneo. Four major bedrock units are out- trafficability conditions occur during the summer, while the lined on FIGURE II 44: the generally unconsolidated qua- worst conditions occur during the winter. ternary sediments of the coastal lowlands and interior basins, In the central part of Mindanao, the precipitation is generally the poorly consolidated tertiary sediments lying between the in- less at the lowland stations than in the northeast. Although terior mountains and coastal lowlands, the volcanic rocks of the there is considerable variation from place to place, trafficability Darvel Bay and Cowie Harbor regions, and the consolidated in Veruela is generally best during the winter, and least favor- pre-tertiary rocks of the interior mountain country. The soils able during summer and fall. developed through lateritic weathering from all of these rocks Along the southern coasts, and particularly the southwestern should be friable, permit rapid drainage of excess water, and be coasts, weather conditions are more conducive to good traffica- trafficable except during and immediately after heavy precipi- bility than they are elsewhere. Glan has an average annual rain- tation. Those derived from rocks such as shales, with fine-tex- fall of 58 inches, and Zamboanga receives only 42 inches. In tured clay components predominating, have less favorable this area, the most favorable season is winter while the least drainage properties, are probably very slippery when wet, and favorable conditions occur during summer and fall. require more time to regain trafficability after periods of rain. Soil information is not available for the southern part of the E. Sulu Archipelago. Borneo sector of the Celebes Sea Area. The limited geologic in- The soils of this area are of 3 general types, when con- formation concerning that region indicates that the soils occur- sidered on the basis of their trafficability. ring there are probably of similar trafficability to those mapped The first type consists chiefly of sandy soils, developed on in the northern part of Borneo. uplifted coral reefs, and found on most of the low islands on The unconsolidated alluvium of the coastal areas is least either side of the central arc. These islands include the Pangu- trafficable near the mouths of the rivers and between the nat- taran group and those to the southwest including Laparan, ural levees and the better-drained hill slopes. The interior basins Dammai, Sibutu and its adjacent islands, as well as Simunul and are floored with interbedded silt, sand, and coarse gravel, and the low islands of the Tawitawi, Samales, Tapiantana, and although trafficable when dry are periodically flooded and non- Pilas groups. Many of these islands, including Tongquil and trafficable. Heavy forest and rough mountain topography pro- those islands between Tongquil and Jolo in the Samales group, vide serious obstacles to vehicular movement in the interior Kaludlud and Dassalan in the Pilas group, Mantabuan and ad- regions. jacent islands in the Tawitawi group, Cabingaan island in the Extensive swamps and marshes occurring at the mouths of Tapal group, and practically all of the islands in the Pangutaran the major rivers and along parts of the coastal lowlands should group, are largely covered with impassable mangrove swamps. be considered nontrafficable at all times unless found by ground Where mangroves are not present the coarse-textured soils are reconnaissance to be usable. There are some low coral islands trafficable at all times. off the eastern coast, such as Maratoea, which have trafficable Among the second type soils some are derived from sedi- soils at all times. Most of the islands, however, other than those ments. These soils occur on the larger islands-such as Tawi- at the mouths of the major streams, have rough topography tawi-in the central part of the arc, and on the high islands of which precludes rapid movement of vehicles. Most of the is- the Pilas, Tapiantana, and Samales groups also on Marungas, a lands just south of Darvel Bay are of this type. small island just north of Jolo. Soils derived from recent vol- The annual rainfall in Northeastern Borneo averages about canic rock and unconsolidated volcanic ash occur on the larger 100 inches but is variable and probably higher on the exposed islands of the Tapul group, Jolo, on the high islands in the Pilas, mountain slopes. South of Tawau, the most favorable season for Tapiantana, and Samales groups, and the separate island of movement of vehicles is summer, but north of Tawau this con- MILITARY GEOGRAPHY Page Il 29 dition is less apparent and there is little consistency in the sea- Plan 2, which should be studied concurrently with the text ma- sonal precipitation records from station to station. terial given below: G. Northern Celebes. A. Natural vegetation. From what is known of the soils of the northern peninsula Certain general vegetation types are common to all the of Celebes, it appears that they are similar to those of Halma- islands of the region, but the distribution and the relative hera. Because of incomplete information, much of this area cannot be mapped as to soil type. Furthermore, the coarse- and amount of area covered by each type vary greatly, depending upon population density, rainfall, drainage, and soil. There is medium-textured soils have not been separated. These coarse- also considerable variation within the types themselves, depend- and medium-textured soils cover large areas especially in the ent upon the same factors. The main vegetation cover types eastern part of the northern peninsula of Celebes. They are de- are briefly described in the following paragraphs. rived from consolidated and unconsolidated volcanic ash, from granite and granite-like rocks, from miscellaneous consolidated (1) Rain forest. sediments including sandstone, shale, conglomerate and lime- This is the original type of forest cover on most of the island stone and from coarse- and medium-textured alluvium. They areas, but it has been greatly reduced in many places by human probably extend from one coast to the other in some places and activities. It still covers most of the rough, uninhabited terrain. are found also on many of the off-lying islands, particularly Particularly characteristic is the very dense overhead canopy, those along the north coast. As a group they should be traffic- 100 to 140 feet in height, which shuts out almost all sunlight able where topography permits except during and immediately and renders the floor of the forest dark and damp. Species of after heavy precipitation. trees are numerous and varied, and with few exceptions, the Much of the interior of Celebes is mountainous and heavily trees are broad-leafed. There also are numerous species of vines forested and therefore nontrafficable, regardless of weather. (lianas), creepers, and ferns. The trees stand close together, and There are numerous small coral islets along the coast of north- the trunks are free of branches to a considerable height. Many ern Celebes, particularly in the Gulf of Tomini, which have trees send out roots at some distance above the ground which coarse-textured soils which are trafficable at all times. spread to a radius of several yards. The trees are often dripping So far as is known, fine-textured soils cover large areas only with moisture. near the western end of the northern peninsula of Celebes. Two types of rain forest may be recognized: These soils are derived from micaceous rocks, soft-sheared basic (a) Rain forest with sparse undergrowth. (FIGURE Il metamorphic rocks, limestone, and fine-textured alluvium. 34). There is an absence of thick undergrowth due to the small Where topography is favorable, these soils should be trafficable amount of light which reaches the floor of the forest. Visibility except during and after heavy precipitation. Slippery when wet, is poor, due to close spacing of trees and dim light. The under- they require somewhat longer to dry out and regain trafficabil- growth offers little obstruction to free movement of men on ity after precipitation, than do the coarse- and medium-textured foot, except for small detours to avoid lianas, fallen trees and soils. thorny palms. The close stand of the trees, together with fallen Soils of less favorable trafficability occur at the mouths of the trees, prohibits movement of motor vehicles. Often too, the major streams. These soils are trafficable when dry, but are fre- ground is very wet and soggy. quently flooded and impassable during periods of heavy pre- cipitation, As in the Halmahera Sector, there are fairly large areas of swamps and marsh land at places along the coastal lowlands. These areas are always nontrafficable. In addition, narrow coast- al strips of mangrove swamps occur at many places. Thin residual soils predominate in the mountain areas of Celebes. Although some of these areas between 1,200 and 4,500 feet have been mapped, many of the unmapped areas are also mountainous. In such areas, vehicular movement is impeded more by the rough topography than by soil or weather condi- tions. The average annual rainfall in northern Celebes is about 90 inches. It is highest in the northern part where it averages 101 inches, and lowest in the southern part where it averages 78 inches. Lowest average annual rainfall occurs on the southern coast at Gorontalo, where it is 48 inches, and at Tinombo where it is 50 inches, Trafficability conditions are most favorable dur- ing summer, less favorable during fall and spring and least favorable during winter. 24. Vegetation FIGURE Il 34. New Guinea. Rain forest with comparatively sparse undergrowth. Characteristic also Vegetation distribution in the Celebes Sea Area is shown on of rain forests in Celebes Sea Area. Page Il 30 MILITARY GEOGRAPHY (b) Rain forest with undergrowth. (FIGURE II . 35). ficult and sometimes dangerous, due to concealed obstructions Where sufficient light penetrates the overhead canopy, there is or rock fissures. Cover is as complete as in the rain forest and thick undergrowth. Such areas are found marginal to the rain visibility is usually restricted to a few yards. forests or occur on steep slopes and along streams. The floor of the forest is covered with a jungle of vines, bushes, palms, bam- boos, and other undergrowth. Movement is extremely difficult and slow due to the necessity of hacking a way through the tangled vegetation. The overhead cover is quite as complete as in the more open rain forest. Horizontal visibility is usually re- stricted to a few feet. FIGURE Il 36. New Guinea. Moss forest. Typical also of large parts of forested areas in Mindanao, Borneo, and other lands of Celebes Sea Area. (4) Mangrove swamp. FIGURE II 35. New Guinea. Mangrove trees grow thickest along protected coasts with Rain forest bordering river where light penetraring under trees encour- ages heavy undergrowth. Similar conditions are found along forest edges low, muddy, flat lands, especially about the mouths of streams and on steep slopes in Borneo, Mindanao, and other parts of Celebes or along their lower courses. The trees are of fairly even height, Sea Area. commonly 20 to 40 feet or more. They are close-set and send out a tangle of prop-roots growing from the trunks at a wide (2) Second growth. (FIGURE II 1). angle, as much as 10 feet above the ground. Underneath, the This type of forest occupies areas once cultivated, on which ground is likely to be thick, slippery mud, which may be covered the forest has again taken possession but has not reached ma- with water at high tide. A network of narrow, fairly deep water turity. Vegetation of greatly varying height and density may be courses is likely to interlace the swamp area. The swamps are found within the same local areas, depending upon the age of very difficult to penetrate, both because of the tangle of prop- growth. Within the cut-over forest, patches are cleared for cul- roots and because of mud or water. tivation each year, then abandoned after two or three years. Seen (5) Nipa swamp. from above, small areas of growth of varying height give a Nipa palms occupy the drier and less salty areas beyond man- spotted appearance. Such forests predominate in northern Bor- grove swamps. Patches of them may be distributed like islands neo and in considerable areas in Halmahera. Early stage second within the larger mangrove areas, particularly in deltas. The growth consists of thickets of tangled bush, brambles, and creep- fronds of the trunkless palms (10 to 15 feet high) grow ers, which may be interspersed with large trees and stumps. straight out of the ground, which is usually thick mud or even Movement may be as difficult as in rain forest with under- shallow water. The palms grow very close together with the growth. Cover is complete for men, but it may be difficult to stiff and tough leaves against each other or interlaced. The conceal motor vehicles completely in areas of relatively young palms are lighter in color than the mangroves. Movement is second growth. Bamboo thickets are common as second growth, extremely difficult due to the dense growth and the lack of solid especially in Halmahera and Mindanao. footing. Concealment is usually complete, and visibility is (3) Moss forest. (FIGURE II 36). limited to a few feet. This type occurs in the higher altitudes, above 6,000 feet (6) Swamp forest. (FIGURE Il 37). near the Equator, but extends to lower altitudes as one goes from Swamp forest is commonly found in conjunction with sago the Equator. In northeastern Mindanao and in some parts of Bor- palm swamps in those areas where accumulation of mud or silt neo its lowest occurrence is at about 3,500 feet. This forest occu- has been sufficient to leave these areas comparatively dry during pies areas in which evaporation is practically nil, and generally the dry season, although covered with water during the wet conforms to the zone of greatest cloudiness. It is dripping wet, season. Trees with prop roots or roots which extend from the and the atmosphere is gloomy, cold and depressing. A layer of base of the trees in large slab-like projections are especially moss and decayed vegetation covers the ground, to a thickness characteristic. Individual trees may be 100 feet or more in of several feet, covering fallen trunks and branches. The trees height. The swamp forest may resemble somewhat a rain forest are also covered with lichens and festoons of moss. As a rule, with a fairly thick undergrowth of smaller trees and shrubs. the forest consists of a thick undergrowth of slender unbranched Thin stands of sago palms may be included. Except for vines, trees. Sometimes the trees are dwarfed. The forest is silent due palms, and some bushy undergrowth, movement in the swamp to nearly complete absence of bird, animal, and insect life, and forest during the dry season may be as easy as in the rain forest to the absorption of sound by the moss. Movement is very dif- with sparse undergrowth. In some parts of Halmahera the MILITARY GEOGRAPHY Page Il 31 swamp forest is composed of almost pure stands of sago palms. cult but not impossible. The heat may be almost unbearable, Sago is also fairly abundant in the swamp forests of northern due to lack of breeze and shade. Motor vehicles can move Celebes. through the grass without great difficulty. Planes can make FIGURE II 37. New Guinea. Swamp forest. Typical also in Celebes Sea Area. (7) Marsh grass, sedge, and wild cane. emergency landings with wheels up in tall grass. Troops can Large areas of floating grasses and sedges are found in the find cover from ground view, and fair cover from air view. interior of Mindanao (FIGURE Il - 20). Wild cane, called "pit Visibility varies from excellent in short grass to a couple of feet pit" in New Guinea, resembles tall reeds and grows densely to in the tallest and densest grass. a height of 12 feet (FIGURE II - 38). It frequently fringes the banks of rivers, but does not cover large areas, Floating grass (9) Special types of vegetation. areas have no footing, and can be crossed only by canoe where There are several types of plant growth which are found in narrow waterways have been opened. Wild cane may grow in relatively small areas, and are of only local significance. They several feet of water. include: (a) the casuarina forest, a sparse growth of low trees with needle-like foliage, found on sandy ridges along the beaches (8) Open grassland. (FIGURES II . 3 and II - 39). and easily penetrable by troops; (b) scrub and dwarf forests at Extensive natural grasslands are found in Mindanao in the high altitudes, limited to a few mountain summits, with trees areas of lesser rainfall. On other islands grasslands are limited in growing densely to heights of 10 to 20 feet; (c) alpine vegetation area, developing generally after cultivation. The common type of scrub and grass on the highest summit areas, as on Mount of grass is known as "cogon" in the Philippines and elsewhere as Kinabalu in northern Borneo. "alang alang" or "kunai." It is very coarse and dense, growing B. Cultivated lands. usually to a height of 4 to 6 feet, but occasionally up to 12 feet. The blades are about 1/2 inch wide and have serrated edges. The The total area of land actually under cultivation-is relatively natives burn off large areas in the dry season, but the grass small. The island of Mindanao includes much the greater part. quickly grows back to maturity. Travel on foot in cogon is diffi- Two distinct types of cultivation should be noted: Page Il 32 MILITARY GEOGRAPHY FIGURE II 38. Mindanao. Wild cane at crossing on upper Agusan River, near Compostella. This growth is characteristic of low muddy stream banks clearings which are cultivated for 2 or 3 years and then aban- doned for new sites. Grass and second growth forest then take possession. In a few local, more densely populated areas in Min- danao, Minahasa, and northwest Borneo, cultivated fields and abandoned open grassy patches are more or less continuous. Rice paddies, common along the stream valleys of Borneo, Celebes, and some parts of Mindanao, are cultivated from year to year (FIGURE II 33). Corn is the chief crop in the shifting clearings. Some yams, bananas, taro, sugar cane, and vegetables, are also grown. In areas of shifting clearings the cultivation is spotted amid second growth in various stages. C. Distribution of vegetation in Halmahera. The island is almost entirely covered with rain forests in which it is difficult to make progress due to vines. Coconut FIGURE II 39. Mindanao, Cotabato Basin. Buldun. Looking NE. 1939. Tpyical open stand of palms or plantations extend along much of the coast. Back from cogon grass. the coast, a belt of plains, hills, and valleys includes native (1) Plantations. clearings, local grass areas and considerable second growth. The grass, here called "alang alang," corresponds to the "cogon" These are found chiefly on the better drained sandy lands of of the Philippines and the "kunai" of New Guinea. the coastal plains, although in Mindanao there is much scat- tered cultivation of the plantation type in inland valleys and (1) Southern Halmahera. plains, Coconut plantations are by far the most common. They Most of the coast is bordered by coconut trees and groves. In- are located on or near the coasts. Next in importance are abaca land, the country is uninhabited and covered with dense rain (hemp) plantations in Mindanao, and rubber in northeast forests, which extend to the coast of the southern extremity and Borneo. Of minor importance are tobacco and coffee plantations some parts of the east coast. On the west coast there are scat- in North Borneo, and pineapples in Mindanao. Plantation vege- tered small coconut plantations between Semo and Lifofa, and tation generally permits free movement on foot or by motor native clearings and second growth in a narrow belt back of the vehicle, except in neglected coconut groves where young coconuts coast. On the northeast coast, around Weda and Foja, and in and other undergrowth have come up. Well-kept plantations the river valleys between, a pattern of coconut plantations, na- have networks of roadways. The coconut trees usually are plant- tive clearings, grass areas and second growth extends some miles ed in rows far enough apart (ordinarily about 30 feet) to per- inland. Mangrove swamps are found at the mouths and along mit movement of motor vehicles between. Abaca plantations the lower courses of the larger streams on the east coast, north often are traversed by roads, and the plants, although 10 to 18 of Foja. The coast north of Maidi is swampy, and swamp land feet high, have shallow roots and are easily pushed over by extends inland between Maidi and Lifofa. Damar Island is en- tanks and trucks (FIGURES II 6 and II 40). tirely covered with rain forest. (2) Cultivated fields. (2) Central Halmabera. The most common practice of the natives is to make small Mangrove swamps extend along much of the west coast be- MILITARY GEOGRAPHY Page II 33 tween Pajaheislam and Akelamo and for a few miles north of Akelama, as well as along stretches of coast on the southeastern peninsula. Coconut groves are found along most of the west coast, also along the coast of the southeastern peninsula and some stretches of coast on the northeastern peninsula. Most of the streams have mangrove swamps at their mouths and along their lower courses. Farther inland there are grassy areas along the bottoms of the main stream valleys. There are occasional grassy marshes. Native clearings and second growth occur on the coastal lands of the southeastern peninsula and along the south coasts of the northeastern peninsula. All the interior is covered with dense rain forest. Much of that near the coasts has heavy undergrowth. (3) Northern Halmabera. The interior is densely covered with rain forest, but there is relatively more cultivation and grassland than in other parts of Halmahera. North of Djailolo is an area of well-kept coco- FIGURE II 40. Mindanao. nut plantations, scattered fields, and areas of abandoned culti- Lanao Uplands. Alubijid west of Cagayan. 1939. Abaca plants. vation which have gone into grass or have reverted to various stages of second growth (FIGURE II 1). On the east side of the D. Vegetation distribution in the Sangihe-Talaud Is- peninsula, the plain of the lower Kaoe River has considerable lands. areas in grass. There are also many scattered cultivated spots. All of the intermediate mountain slopes of the larger islands Coconut groves extend along the coast from Malifoet north to are covered with forests. Coconut groves are continuous along Tobelo. A belt of grassland parallels much of this coast. The the sandy coasts and on well-drained coastal plains. Native country around Tobelo and Galela is also a mixture of coconut clearings, gardens, and second growth extend up the lower plantations, native clearings, second growth, and grassland. slopes of the mountains. The higher volcanic slopes are barren, Grasslands extend northward over the Galela Plain. On the west or covered with dense low brush. Occasional mangrove swamps side of the peninsula there are plantations around Baroe on the are found on sheltered low coasts. Some of the smallest islands coast and extending inland around Iboe. There are mangrove are almost entirely covered with coconut palms. swamps at the heads of Galela and Djailolo Bays. E. Vegetation distribution in Mandanao. (4) Morotai Island. The greater part of the rough terrain on the island is forested. Coconut palms fringe all of the south and east coasts. There The forests are most nearly continuous in the eastern part of the are also considerable areas of marsh land, especially at the river island, on the western peninsula, and in the Southern Mountain mouths on the southwest coast. Grasslands or bamboo thickers Region. There are extensive grasslands, however, throughout extend in narrow bands inland along the streams. All of the rest the central part, and some grasslands in the west coastal regions. of the island is dense rain forest. Districts where cultivation is shifted frequently and in which (5) Western Volcanic Islands. considerable areas of second growth occur, are widely distrib- uted. The better drained lowlands have abaca plantations or Ternate has a considerable amount of cultivated land. Many permanently cultivated fields of rice, corn, sugar cane, and other villages and fields dot the coastal region though they are more crops, isolated inland. All of the southern slopes of the mountain are dotted with gardens. Rain forest with undergrowth and second (1) Southern Mountain Region. growth cover the rest of the mountain sides. The top of the vol- This region is an almost unbroken forest. A belt of moss forest canic cone is barren or covered with grass and brush. There are covers the higher mountain ranges, paralleling the coast inland a number of coconut plantations around Kajoa. The other is- and west of Sarangani Bay. There are several small areas of lands have scattered clearings and second growth along the moss forest east of the bay also, on the range paralleling the coast, grading into rain forests in the interior. Mangrove Pacific Coast. Open grass country extends inland from the north swamps are common along the east coasts of Tidore, Kajoa, and coast of Sarangani Bay. At the western end of the region, north Laloein. of Linao Bay, there is a smaller area of mixed grassland and forests, and all along the coast a narrow belt of scattered fields, (6) Batjan Islands. occasional coconut plantations and much second growth. Coconut groves fringe most of the coasts. Plantations are fair- ly continuous on Barian Island south of Laboeha. Inland from (2) Central Mountain Region. Laboeha, sago swamps extend toward Babang Bay. There are a Except near the north coast, this region is covered by almost few small areas of grassland and bamboo in the interior valleys. continuous rain forest. There are two small areas of moss forest Most of the area of the islands is covered with rain forests. Man- in the mountains east of Macajalar Bay. On the east coast of grove swamps extend along the south coast of Mandioli and Macajalar Bay there is a belt of villages, scattered fields and along Sambaki Strait. grasslands, and farther inland an area of mixed grassland and Page Il 34 MILITARY GEOGRAPHY forest. Bordering the streams, the forests have dense under- (7) Lanao Uplands. growth, but inland they are comparatively open. Around Lake Lanao, and northward to Iligan Bay, the coun- try is open and grassy, with much of it under cultivation, rice be- (3) Davao Lowlands. ing the chief crop. East of Lake Lanso, the long slopes leading Cultivation is more extensive in this region than elsewhere to the drainage divide are covered with dense wet forests. Some in Mindanao. There are extensive plantations of abaca extend- moss forest is found on the mountain slopes southeast of the ing back from the coast, especially up the Davao, Talomo and lake. South of the lake the country is forested, but nearer the Daliao River valleys. (FIGURE II - 6). There is a network of coast the forest is only scattered. In the vicinity of Malabang on private roads through these plantations. Many coconut planta- Illana Bay, the coastal region is open grass with considerable tions border the coast. Mangrove swamps fringe much of the scattered cultivation and extensive coconut plantations. coast north of Davao and around the head of the bay. These swamps are most extensive at the mouths of the rivers, especial- (8) Western Mindanao. ly the Hijo, Tuganay, and Padada rivers. Sporadic native cul- Rain forests cover much of the area and are particularly tivation with second growth is characteristic of the lower east dense on the slopes of the mountains to the north and east. A and south slopes of Mount Apo, and the river valleys extending considerable mountain area west of Iligan Bay is covered with inland from the northern part of Davao Gulf. moss forest. The coastal regions tributary to Sibuguey Bay, and on the opposite north coast, are mostly in cogon grass. Grass (4) Eastern Mindanao. also covers much of the uplands to the north, and open, partly Dense forests cover all of the region except for small cul- cultivated country extends up the Sibuguey Valley. There is tivated areas along or near the coasts. Most of the forest has also a stretch of grass country berween Dumanquilas and Illana comparatively sparse undergrowth, but on the narrow coastal Bays, but Baganian Peninsula is forested. The coastal region plain there is considerable dense second growth in areas for- west of Iligan Bay is quite densely populated and has coconut merly cultivated. Mangrove swamps are not common on the groves on the low ground back of the beach. Mangrove swamps east coast except for about 10 miles of coast southeastward from fringe much of this coast. They are quite extensive around the Surigao and a small area at the head of Lianga Bay. Along the head of Panguil Bay and on the deltas of the Sibuguey and coast there are scattered, small, settled areas where the natives Kumalarang rivers. Mangrove swamps also fringe much of the grow rice, hemp, and coconuts. Cultivation is most extensive coast to the east and northeast of Zamboanga. Coconut groves in the north, between Surigao and Lake Mainit. Extending in- extend along the coast at the south end of the Zamboanga land from the coast, north of Carrascal for about 15 miles, there Peninsula (FIGURE II - 18). The Goodyear rubber plantation is a large area of red soil, barren of vegetation. There are 2 is located at Kabasalan, 3 miles inland and north of Sibuguey fairly large areas of moss forest; one in the mountains east of Bay. The coastal lands sloping toward Dumanquilas and Paga- Davao Gulf, and the other in the Diuata Mountains. In the lat- dian Bays have much second growth interspersed with culti- ter area the moss forest extends downward as low as 3,500 feet vated patches (FIGURE II -17). and in the southern mountains down to about 4,000 feet. The forests of this region are the wettest in Mindanao. (9) Cotabato Basin. Four types of country are included: grasslands, mixed grass (5) Agusan Basin. and forest, swamp, and cultivated lands. Mangrove swamps Rain forests cover most of the Agusan Valley. There are cover much of the delta lands of the Pulangi-Mindanao River. mangrove and nipa swamps at the mouth of the Agusan River Upstream from the delta, the flat lands bordering the lower which extend up the river about 2 miles. Beyond this, both Pulangi-Mindanao river are mostly in rice fields, especially banks are covered with coconut trees. The east bank of the around Cotabato (FIGURE II . 33). Grasslands extend from river is generally lower and swampier than the west bank and the coast southeastward over the plains of the Alah and Bunga has considerable wild cane and swamp forest. Swamp areas ex- rivers. Scattered forest and grass cover the northern part of the tend along the east side south of Butuan for several miles. Be- Cotabato Basin. The Libungan and Liguasan marshes cover tween Butuan and Esperanza there is low-lying farm land. Up- extensive areas through the central part. They are mostly COV- stream from Talacogon there is an extensive area of marsh, ered with floating grasses (FIGURE II 20) or reeds, merging in- with floating grasses and sedges, and with strips of swamp bor- to forest on the slightly higher natural levees along the rivers dering the river. The swampy area extends for 15 to 20 miles (FIGURE II - 10). At Kusiong, on the coast south of the delta, back from the main channel, on both sides. there is an abaca and a coconut plantation. Inland, there is a (6) Bukidnon Uplands. rubber plantation at Kabacan. Bongo Island, off the coast, is mostly covered with patches of coconut trees. Cogon grass (kunai) covers all of the northern and eastern parts, in the drainage basins of the Pulangi, Cagayan, and Ta- goloan Rivers (FIGURE II 3). The grass is exceptionally high F. Vegetation distribution in Sulu Archipelago and Basi- lan Island. between Bugo and Alae in the northern part. The grasslands are broken by scattered fields, especially near the coast of Maca- Many of these islands (particularly those in the central por- jalar Bay and along the road south of Cotabato. Corn and up- tion) are extensively cultivated by the natives. The fields are land rice are important crops. The Katanglad and Kalatungan well laid out and cultivation is continuous. Areas of second Mountains, in the western part, are forest-covered. The higher growth are subordinate, but increase in proportion inland, giv- areas are in moss forest. The Del Monte pineapple plantation ing way to rain forests on the steeper slopes. The more rugged extends for about 7 miles northward from near the base of the islands are almost entirely covered with forests with little or no Katanglad Mountains. cultivation. Mangrove and nipa swamps border the sheltered MILITARY GEOGRAPHY Page Il 35 coasts of the larger island, and completely cover some of the ests tend to have considerable undergrowth except where it has small low islands. been cut. Native clearings and also spots of second growth are (1) Basilan Island. sparsely scattered through most of the forested regions. Nearly all the trees are broad-leafed. Along the main valley bottoms More than half of the island is forested. Native cultivation there is relatively much more cultivated land. Practically all the is extensive, and there are several small rubber plantations in rest of the land has been under cultivation fairly recently and the northern and eastern parts of the island between Isabela, has gone to second growth or tall grass ("alang"). Casuarina Lamitan, and Bohelebong. There are also scattered patches of forests are characteristic along the coast. Mangrove swamps cultivated land and much second growth along the south coast. border the coast line, especially at the mouths of the rivers Mangrove swamps extend along much of the southwest and where they are bordered inland by nipa palm swamps. southeast coasts, (2) Jolo Island. (2) British North Borneo. The island is very largely under cultivation or in grassland Except for the relatively small areas of cultivated lands and which was formerly cultivated. The fields are contiguous, mod- grasslands, North Borneo is forest-covered. Primary rain forest erately large, well laid out, and separated only by lines of brush with sparse undergrowth are found mainly over the summits or local patches of second growth. The most intensively culti- of the ridges or mountains, above 3,500 to 4,000 feet elevation. vated areas are around Jolo, Maimbung, Parang, and Seit (FIG- The lower forests are all cut-over, having been partly cleared URE II - 23), adjacent to the coast, and around Talipaw in the by the natives for their products. Beginning near the coast the interior. Most of the fields are open, but many groves of tropical forests, therefore, have dense undergrowth which becomes more fruit trees are included. Only a few minor areas of mountain or sparse until the primary undisturbed forest is reached. The for- hill country remain in forest. There are mangrove swamps ests include more than 500 species of trees, nearly all of them along parts of the south coast. The larger islands of the Tapul broad-leafed. In the Crocker Range, in the western part, most group (including Pata, Tapul, Lugus, Lapac, and Siasi Islands), forests occur at elevation above 5,000 or 6,000 feet. On Mount south of Jolo Island, are similarly largely under cultivation, but Kinabalu, dwarf forests and scrub cover the slopes above the include areas of second growth and forest (FIGURE II 26). moss forest. The flat lands along the coast are grasslands for the most (3) Tawitawi Island. part, within which there are cultivated areas, mostly in rice. In the southwestern part of the island open cultivated fields, The hill lands near the coast are largely covered with second grassy patches, and second growth cover the landscape (FIGURE growth. The hill or mountain zone comes much closer to the II - 25). In the eastern part of the island, patches under cultiva- west coast than to the east, and forested mountain spurs extend tion are widely scattered amid second growth which grades in- to the coastline. The valley bottoms include many open areas land to rain forest with dense undergrowth. On other parts of of tall grass, as well as second growth, rice fields, and rubber the island there are only narrow coastal strips having cultivated plantations. Coconut plantations are distributed along the coast. patches and second growth. The interior of the island is covered Minor plantation crops are tobacco, coffee, tea, abaca, and sugar with rain forest. The neighboring small islands off the northeast cane. The system of shifting cultivation has produced large coast of Tawitawi are mostly in rain forest and second growth, areas of second growth on the western side of the major drain- with only isolated clearings. There are coconut plantations on age divide, Mangrove and nipa swamps occur at the mouths the southwestern tip of Sanga Sanga Island. On Simunul, south of the rivers, and on the east side, where the rivers have less of Tawitawi, there are coconut groves along the coast and current, the swamps extend up stream, giving way inland to scattered clearings and second growth farther inland (FIGURE fresh water swamp forests. II - 27). Manuk Manka Island is covered with second growth and rain forest having dense undergrowth. Broad areas of man- H. Vegetation distribution in Celebes (north of the Equa- grove and nipa swamps are almost universal along the eastern tor). coast of Tawitawi and along the shores of the numerous, small Rain forests cover the mountains, which comprise the major neighboring islands. portions of the region. Some parts of the coastal plains tend to be swampy. At the eastern extremity of the peninsula the popu- G. Vegetation distribution in Northern and Eastern lation is fairly dense and much of the area is in cultivation. The Borneo. well drained portions of the coastal plain are almost entirely More than 80% of the area is forested. Primary rain forests under cultivation, with coconuts, rice, and corn as the principal with sparse undergrowth extend over the ridge summits, but crops. on the lower slopes and plains the forests have heavy under- growth, becoming thinner inland. They include occasional (1) Minabasa-Bolaäng-Mongondow. clearings and areas of second growth. Along the stream valleys Rain forests with sparse undergrowth cover the mountains, the land is almost entirely in scattered fields, grass, and second especially toward the west side. Toward the east coast the for- growth. Casuarina forests border much of the coast which is ests are comparatively dry and there are local valleys with al- not in swamp. most arid vegetation including masses of cacti. In most places, the coastal plain and also the foothills are covered with tall (1) Dutch Borneo (north of the Equator). grass, called "alang alang," (cogon or kunai). Grassy areas Rain forest covers much the greater part of the region. Many with native clearings ("ladangs") and plantations extend also of these forests are utilized or worked by the natives for both up the lower slopes of the volcanic mountains (FIGURE II 41). commercial products and for their own sustenance. These for- Considerable flat land is under cultivation with native fields of Page Il 36 MILITARY GEOGRAPHY FIGURE II 41. Celebes. Minahasa Region. Exact locality and date unknown. Native clearings ("ladangs") with upland rice and some palms. Rain forest in background. rice and corn and plantations of coconuts, rubber, some tobac- sago. The largest area of swamps is on the delta of the Ran- CO and coffee. Wet rice paddy fields ("sawabs") surround Ton- dangan River on the south side of the peninsula. Coconuts are dano Lake. Nipa and mangrove swamps are common at the universally present along sandy shore lines. mouths of the larger streams and behind the sandy beaches. (2) Nortbern Peninsula, This region is almost completely covered with rain forests. 25. Regional Summary The coastal plains include limited areas of cultivation and sec- The relief, drainage, vegetation, and water supply of the ond growth. The swamps on the coastal plains include man- Celebes Sea Area are summarized by terrain regions in TABLE grove and nipa near the shores, and, farther inland, considerable II 1 below: TABLE II I MAJOR AREA TERRAIN REGION RELIEF DRAINAGE VEGETATION WATER SUPPLY Halmabera Southern Halmahera Narrow coastal plains; Small mountain hilly to mountainous in- Rain forest; narrow strips Wells and streams streams; muchswamp of coconut plantations rerior. on coastal plains. along the coast. Central Halmahera Mountainous: few scat- Sangadji River: small Rain forest in the interior; tered coastal plains; NE Wells and streams. mountain streams; cultivation and second Peninsula, the most rug- narrow swamps. ged. growth on coastal strips. Northern Halmahera Open plains; rolling Kaoe River: other (Kaoe-Tobelo Low- country; dissected ter- Much second growth; some Wells and streams. streams small: lands and Ridges) grasslands in lower Kaoe races. swamps in middle valley; coconut planta- Kaoe valley and near tions along the coast. Akelamo. Northern Halmahera Low mountains; steep Lamo River and Rain forest. Streams