Digitized by the Internet Archive in 2016 https://archive.org/details/guamoperationsofOOunit JSCT‘ 3 0 GUAM Operations of the 77th Division (21 July -10 August 1944 ) American Forces in Action Series Historical Division WAR DEPARTMENT WASHINGTON, D. C. American Forces in Action Series To Bizerte With the II Corps (23 April 1943—13 May 1943) Papuan Campaign: The Buna-Sanananda Operation (16 November 1942 — 23 January 1943) Salerno: American Operations from the Beaches to the Volturno (9 September — 6 October 1943) Volturno: From the Volturno to the Winter Line (6 October — 15 November 1943) Merrill’s Marauders (February — May 1944) Fifth Army at the Winter Line (15 November 1943 — 15 January 19 44) Omaha Beachhead (6 June — 13 June 1944) The Admiralties: Operations of the 1st Cavalry Division (29 February — 18 May 1944) Guam: Operations of the 77th Division (21 July — 10 August 1944) ii Foreword In a nation at war, teamwork by the whole people is necessary for victory. But the issue is decided on the battlepeld, toward which all national effort leads. The country’ s fate lies in the hands of its soldier citizens; in the clash of battle is found the final test of plans, training, equipment, and — above all — the fighting spirit of units and individuals. AMERICAN FORCES IN ACTION SERIES presents detailed accounts of particular combat operations of United States forces. To the American public, this record of high achieve- ment by men who served their nation well is presented as a preface to the full military history of World War II. To the soldiers who took part in the operations concerned, these nar- ratives will give the opportunity to see more clearly the results of orders which they obeyed and of sacrifices ivhich they and their comrades made, in performance of missions that find their meaning in the outcome of a larger plan of battle. DWIGHT D. EISENHOWER Chief of Staff iii WAR DEPARTMENT Historical Division Washington 25, D. C. 1 February 1946 The seizure of Guam in July-August 1944 added another base to our growing chain of possessions encircling the Japanese homeland. Marine troops made the initial landings on Guam and were aided in capturing the island by army units, comprised chiefly of the 77th Infantry Division. Guam tells the Army’s part of the campaign. This study is based upon a first narrative prepared in the field from military records and from notes and interviews recorded during the operation by S/Sgt. James M. Burns. The manuscript of this historical officer has been edited and partially rewritten with the help of addi- tional documentation by Mrs. Marjorie Cline of the editorial staff of the Historical Division. Although in published form the book contains no documentation, the original manuscript, fully documented, is on file in the War Department. Two photographs (pp. 43 and 120) are International News Photos; four (pp. 59, 105, 115) are from the Bishop Museum on Oahu; seven (pp. 15, 21, 32, 33, 54, 69, 78) were taken by the U. S. Navy; one (p. 34) is from the U. S. Coast Guard; one (p. 44) was taken by the U. S. Marine Corps; two (pp. 15, 26) were supplied by the Air Transport Command, Overseas Technical Unit. The rest, unless otherwise stated in the captions, were taken by the U. S. Army Signal Corps. Photographs from International News Photos may not be reproduced without the approval of the War Department. Readers are urged to send directly to the Historical Division, War Department, Washington 25, D. C., comments, criticism, and additional information which may be of value in the preparation of a complete and definitive history of the Guam operation. 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A FA— 9 IV Contents Page OBJECTIVE: GUAM 1 Offensive in the Central Pacific 2 Marianas Islands 5 The Island of Guam 13 Enemy Forces on Guam 19 Plan of Attack 23 ASSAULT PHASE 29 Preparations for W Day 29 The Landings 31 Expanding the Beachheads 37 Attack on Orote Peninsula 41 Establishment of Final Beachline 47 Battle of Supply 53 PURSUIT PHASE 57 Reconnaissance of Southern Guam 57 Pursuit to the North . 63 77th Division s Supply Route 73 BARRIGADA 75 The Pursuit Continues 75 Feeling Out Enemy Positions 80 The Gap on the Left 84 Tanks Support the 305th 90 Attempt to Close the Gap 93 North to 0-3 Line 101 FINAL PURSUIT PHASE 107 The 306th Takes Over the Left f5~6 August) 107 Two Japanese Tanks Ill Plans for the Attack on Mt. Santa Rosa 117 Attack onYigo 119 Tank Attack Against the 306th (7 8 August) 126 Push Beyond Mt. Santa Rosa ( 8 August) 127 Mopping Up 129 CONCLUSION 233 ANNEX NO. 1: Abbreviations 135 v Illustrations Page Maj. Gen. Andrew D. Bruce 4 Troops of 77th Division 10 Bluffs Rising 600 Feet 15 The Enemy Task Force 17 General Takashina and Colonel Suenaga 20 Japanese 200-mm Coastal Defense Gun 21 Landing Beaches 24 Hills in Western Coastal Range 26 The First Wave of Landing Craft 32 Small Boats Leave Asan Beaches 33 Waiting for Orders 34 306th RCT Comes Ashore .40 Close-in Fighting 43 Orote Air Strip 44 An Antitank Crew 48 The 2d Battalion, 305th RCT 49 Men of Company B 51 Cranes at Reef’s Edge 52 Bulldozers Cleared Roads 54 Supplying the 77th Division 55 Area Patrolled 59 Pursuit Phase Begins 6l Machine-Gun Nests 64 Company G, 305th RCT 66 Native Camp 69 An Artillery Column 70 Locale of Barrigada Action. 78 The Green House 86 The Wooded Plateau 105 Disabled Japanese Light Tank 113 Mt. Santa Rosa’s Bare Slopes 115 The March to Yigo 120 vi Maps No. Page 1. Allied Advance in the Pacific viii 2. Central Pacific Islands 2 3. The Southern Marianas: Plan of Attack, III and V Amphibious Corps ... . . 8 4. Guam (physiographic map) 12 5. Enemy Dispositions on Guam, July 1944 18 6. Preferred Plan of Attack on Guam, III Amphibious Corps 22 7. W-Day Landing, III Amphibious Corps, 21 July 1944 30 8. Beachheads on W + 1, III Amphibious Corps, 22 July 1944. ... 36 9. 77th Division Sector, 24—27 July 1944 38 10. Orote Peninsula, 1st Provisional Marine Brigade, 25—29 July 1944 42 11. The Gap, 77th Division and 3d Marine Division, 25—27 July 1 944 46 12. Reconnaissance of Southern Guam, 28 July— 2 August 1944 58 13. Pursuit Phase, III Amphibious Corps, 31 July— 1 August 1944. ... 62 14. Construction of New Road, 302d Engineer Combat Battalion, to 31 July 1944 72 15. Approach to Barrigada, 77th Division, 2—4 August 1944 76 16. Reconnaissance of Barrigada, Company D, 706th Tank Battalion, Company I, 305th RCT 80 17. The Gap on the Left, About Noon, 2 August 1944 82 18. Situation on the Right, Close of Day, 2 August 1944 91 19. Company G’s Attack, 1500 — Dark, 2 August 1944 95 20. Barrigada Positions, Close of Day, 2 August 19 44 98 21. Advance to the 0—3 Line, 305th and 307th RCT, 3—4 August 1944 100 22. Plan for Advance, 77th Division, 5 August 1944 108 23. Advance to 0—4 Line, 77th Division, 5—6 August 1944 109 24. Plans for Final Phase, III Amphibious Corps 1 1 6 25. Action at Yigo, 7 August 1944 118 26. Night Positions, 7/8 August 1944 124 27. Guam (in color) Inside back cover vii ALLIED ADVANCE IN THE PACIFIC Allied advance to Mat 1944 Projected attack on Marianas, June 1944 ' Enemy -controlled area, May 1944 500 1000 ■1 / //// ">' NEW ZEALANO MAP NO. 1 Objective: Guam npHE INVASION OF THE SOUTHERN MARIANAS in June and July of 1944 was part of a coordinated effort by U. S. forces to obtain bases within striking distance by air of the Philippines and the Japanese home islands. The enemy position in the Pacific was weakening under strong Allied offensives, which moved along two lines converging on the Japanese inner 2 one. From Australia the Allied offensive had developed on an axis northwest along New Guinea and beyond the Bismarck Sea, and from Hawaii it had moved to the west through the Marshall Islands (Maps Nos. 1 and 2, pp. viii, 2). The advance along both lines had depended upon the conquest of enemy islands selected to form a system of supporting garrisons from which air and sea power could neutralize the remain- ing enemy bases in the area. By late spring Allied forces in the Southwest Pacific, pushing their advance along the northern coast of New Guinea, had reached Biak Island. Their network of forward bases in the Admiralty Islands and on New Guinea threatened Japanese holdings in the Netherlands Indies, the Caroline Islands, and even the Philippines. Eastward of Hollandia more than 100,000 enemy troops, cut from their sources of supply, were ineffective for future operations. To the north and east of the New Guinea thrust, Central Pacific forces had established a line of approach toward the Philippines, severing the enemy’s communications east of Eniwetok atoll. The advance through the Central Pacific, begun a year later than that in the South and South- west Pacific, protected the Allied positions in the Admiralties and on the New Guinea coast by weakening Truk, principal Japanese fleet base and aircraft staging center in the vicinity. The next move, to the Marianas, was daring; it extended the Central Pacific spearhead more than a thousand miles to the west of the Marshalls, between the enemy-held Carolines on the south 1 MAP NO. 2 and Wake and Marcus on the north. The potential value of the southern Marianas was worth the risk. In addition to threatening the Philippines and the enemy supply line to the south, the conquest of these islands would furnish Central Pacific forces with their first bases for large-scale air attacks on Japan. Offensive in the Central Pacific Advance through the Central Pacific to the Marianas by U. S. forces meant penetrating deep into the Mandates, made up of the Marianas, Palau, Caroline, and Marshall Island groups, which the Japanese had controlled since World War I. Except for Guam, a possession of the United States since the Spanish- American War, these islands had been secretly fortified by the enemy prior to 7 December 1941. By overwhelming Guam four days after their attack on Pearl Harbor, and occupying the Gilbert Islands during September and October 1942, the Japanese controlled all the great island chains in the Central Pacific. For more than two years they had been 2 perfecting interdependent land, air, and sea bases on these chains to form a defensive system in depth, guarding their inner empire from attack on the east and south. The offensive on the east, penetrating the chain barrier, had begun on 21 November 1943 under the command of Admiral Chester W. Nimitz, Commander-in-Chief, U. S. Pacific Fleet and Pacific Ocean Areas. The first blow struck by Admiral Nimitz involved the seizure of selected atolls in the Gilberts. His offensive required a powerful naval force, with carrier-based planes superior in fire power and maneuverability to the Japanese land-based aircraft, to make the initial attacks on the enemy defenses. Before the amphibious assault, carrier bombers, assisted by medium bombers flying from South Pacific fields, "softened” the enemy’s position in the Gilberts. A naval convoy transported marine and army ground troops to the beaches, some 2,000 miles southwest of Pearl Harbor, and covered the invasion offshore. The Japanese garrisons fought tenaciously, but were destroyed in three days of fighting. Control of Makin, Tarawa, and Apamama neutralized or isolated all other atolls in the Gilbert group, making a systematic annihilation of each of the enemy’s forti- fied bases unnecessary. On these three atolls engineers developed airfields for advancing the Central Pacific forces toward the Marshalls. Continuing his tactics, Admiral Nimitz pushed the offensive ahead. Carrier groups ranged forward early in December to strike at enemy installations in the Marshall Islands. At the end of the month fighters and medium bombers, taking off from the new Gilbert strips, attacked Jaluit and Mili. A series of air raids reached all important Japanese bases, and some were made unserviceable. On 31 January marines and army troops invaded Kwajalein, an atoll in the center of the group. One of the largest fleet concentrations in naval history sup- ported the landing. Again the Japanese fought hard, but by 5 February they had lost the atoll. The capture of Eniwetok, 350 miles to the northwest, a month later completed the bypassing of the remaining enemy bases in the Marshalls. The two great Caroline and Marianas archipelagoes lay to the west, guarding the Philippines and the enemy supply lines from Japan to New Guinea and the Netherlands Indies. The Central Pacific forces immediately launched air and naval attacks on both groups. Large carrier-plane formations hit Truk in the Carolines late in February, sinking 19 ships and seriously damaging shore installations. 3 MAJ. GEN. ANDREW D. BRUCE, Comtnanding General, 11th Divi- sion and Col. Douglas C. McNair, Chief of Staff, on Agat beach. 4 A strong task force, including hundreds of carrier-based aircraft, at- tacked Saipan and nearby Tinian on 23 February; a small raid by 12 fighters was made on Guam. These were the preliminary actions toward neutralizing the Carolines and preparing for an invasion of the Marianas. During the following months air attacks against the Carolines and Marianas intensified. On 30 March a powerful task force of the Pacific Fleet hit bases in the western Carolines, destroying or damag- ing 46 Japanese ships and 216 planes, and inflicting heavy damage on shore installations. The naval unit in this attack, Fast Carrier Task Force (Task Force 58), under command of Vice Adm. Marc A. Mitscher, had been organized early in the year and was to play an important role in the growing offensive. On 11 June a task force struck at the southern Marianas. Carrier-based planes attacked Guam, Rota, Tinian, and Saipan. On the 13th the force, including battle- ships and cruisers, steamed in to shell Saipan and Tinian. With this series of blows Admiral Nimitz’s air and naval forces had paved the way for a full-scale invasion of the Marianas, despite indications of rapid enemy reinforcement of the islands. This advance into the heart of Japan’s Pacific empire would represent a bound forward of 1,000 miles beyond our most recently conquered base at Eniwetok. Admiral Nimitz’s forces would have to operate at dis- tances from their main bases which once would have been considered prohibitive: 3,300 miles from Pearl Harbor and nearly twice that distance from California. His ability to undertake such an offensive reflected the great increase of American strength in the Pacific since 1942, an increase measured not only in the size of navy, marine, and army forces under his command, but in the potential of ships, weapons, and supplies furnished by war industries as far as 10,000 miles from the combat zone. Marianas Islands A month after the capture of Eniwetok, Admiral Nimitz decided that the southern Marianas were to be the next objectives in the Central Pacific. Strategically located 1,500 air miles from Manila and 1,600 air miles from Tokyo, the islands would provide his forces with bases almost equidistant from the Philippines and Japan, main Allied objectives. Admiral Nimitz’s plan for the use of the southern 5 ORGANIZATION CHART FORCES FIFTH fleet TASK FORCES TASK FORCE 50 COMMANDER VICE ADM RICHMOND KELLEY TURNER (COMMANDER AMPHIBIOUS FORCES. PACIFIC) COMMANDER VICE ADM RICHMOND KELLEY TURNER (SAIPAN) 2d IN COMMAND REAR ADM HARRY W HILL (SAIPAN AND TINIAN) NORTHERN TROOPS AND LANDING FORCE TASK GROUPE 561 (V AMPHIBIOUS CORPS) COMMANDER LT GEN HOLLAND M SMITH (TO 12 JUL 44) MAJ GEN HARRY SCHMIDT (FROM 12 JUL 44) 2d MARINE DIVISION COMMANOER MAJ GEN THOMAS E WATSON GARRISON FORCES COMMANDERS MAJ GEN SANOERFORO JARMAN (SAIPAN) MAJ GEN JAMES L UNDERHILL (TINIAN) 4th MARINE DIVISION COMMANDER MAJ GEN HARRY SCHMIDT (TO 12 JUL 44) MAJ GEN CLIFTON B CATES (FROM 12 JUL 44) 27lh DIVISION EXPEDITIONARY TROOPS RESERVE, COMMITTED ON 16 JUNE (Dtl) COMMANDER MAJ GEN RALPH C SMITH (TO 24 JUNJ MAJ GEN SANOERFORO JARMAN (24-28 JUN) MAJ GEN GEORGE W GRINER (FROM 28 JUN) 6 ENGAGED IN THE INVASION OF THE MARIANAS COMMANOER ADM RICHARD L CONOLLY (TO 10 AUG 44) )M LAWRENCE F REIFSNIOER (10-15 AUG 44) SOUTHERN TROOPS AND LANOING FORCE TASK GROUPE 562 (m AMPHIBIOUS CORPS) GARRISON FORCES COMMANOER MAJ GEN HENRY L LARSEN 3d MARINE DIVISION COMMANDER MAJ GEN ALLEN H TURNAGE t PROVISIONAL MARINE BRIGADE COMMANDER BRIG GEN LEMUEL C SHEPHERO. JR 77 Ih OIVISION COMMANDER MAJ GEN ANDREW 0 BRUCE EXPEDITIONARY TROOPS RESERVE, ATCHO TO m AMPHIBIOUS CORPS 30 JUN 7 Saipan I STATUTE MILES Marianas was to "establish bases for operations against Japanese sea communications and for long-range air attacks against Japan,” to "secure control of sea communications through the Central Pacific,” and to ''initiate the isolation and neutralization of the central Caro- lines.” The principal force assigned to the mission by Admiral Nimitz was the Fifth Fleet, under command of Vice Adm. Raymond A. Spruance. Activities of all major commanders in the Pacific Ocean Areas and of General Douglas MacArthur, Commander of Southwest Pacific Area, were to be coordinated by the Joint Chiefs of Staff in support of the Fifth Fleet. Timing for the invasion depended upon the completion of new Marshall Island bases and the assembly of sufficient troops and supplies. All naval and ground forces designated for the Marianas operation were organized under Joint Expeditionary Troops commanded by Vice Adm. Richmond K. Turner (Organization Chart, page 6). Admiral Turner’s naval command was divided into two echelons, the Northern Attack Force under his immediate command and the Southern Attack Force under Rear Adm. Richard L. Conolly. Turner’s ground units consisted of Expeditionary Troops under Lt. Gen. Hol- land M. Smith. The Expeditionary Troops were in turn divided into two echelons: one, the Northern Troops and Landing Force, composed of V Amphibious Corps, headed by General Smith himself; and the other, the Southern Troops and Landing Force, composed of III Amphibious Corps, under Maj. Gen. Roy S. Geiger. V Amphibi- ous Corps consisted of the 2d Marine and 4th Marine Divisions, both reinforced, and garrison forces; III Amphibious Corps included the reinforced 3d Marine Division under Maj. Gen. Allen H. Turnage and the 1st Provisional Marine Brigade, also reinforced, under Brig. Gen. Lemuel C. Shepherd, Jr., and garrison forces. The army’s 27th and 77th Divisions, commanded by Maj. Gen. Ralph C. Smith and Maj. Gen. Andrew D. Bruce, respectively, were both in expeditionary troops reserve. While carrier-based planes and submarines made photographic studies of the enemy island defenses, the forces, comprising 500 ves- sels and 120,000 assault troops, were activated and assigned their individual missions. On D Day Northern Troops and Landing Force was to land on Saipan and then prepare to seize Tinian (Map No. 3, page 8). Capture of Saipan would help cut off the flow of enemy 692437 ° — 46—2 9 reinforcements to Tinian, Rota, and Guam to the south. On W Day, Southern Troops and Landing Force was to invade Guam. The 27th Division was to be in floating reserve for any one or all three of these proposed operations. The 77th Division was to be held in strategic reserve in the Hawaiian Islands. D Day for Saipan was set for 15 June. W Day for Guam, designated tentatively as 18 June, depended upon the progress of land operations on Saipan and upon the move- ments of the enemy fleet. Northern Troops and Landing Force proceeded to Saipan as planned. On the beaches the marines suffered heavy losses from mortar and artillery fire. The 27th Division was committed on D + 1, and the Southern Attack Force was brought in as floating reserve. After ten days of bitter fighting, marine and army units occupied approximately one-half the small island. The advance TROOPS OF 77th DIVISION embark from Oahu for Guam to join III Amphibious Corps. Soldiers carry battle packs and duffle bags. during the last days of June was slow and costly, and not until 9 July was all organized enemy resistance declared at an end. The battle cost the 27th Division alone 4,038 casualties. Enemy ground opposition on Saipan, combined with a powerful surface attack, slowed up the whole Marianas operation. Fifth Fleet’s forces were engaged entirely in protecting Joint Expeditionary Troops at Saipan. Even if the Southern Troops and Landing Force was considered strong enough without reserves for the Guam inva- sion, the fleet could not cover the landings as planned. On 16 June the battleships of the Southern Attack Force, initially scheduled to support the Guam invasion, maneuvered to the north of Saipan, while Admiral Mitscher’s Fast Carrier Task Force moved westward into position in the Philippine Sea to protect the troops at Saipan from an impending enemy fleet attack. The next day cruisers and destroyers of the Southern Attack Force reinforced the Fast Carrier Task Force west of the Marianas. The enemy fleet attack materialized on 19 June when the Japanese Fleet Striking Force launched carrier planes against Admiral Mitscher’s task force. The enemy planes made three heavy but uncoordinated assaults. Mitscher’s fighters met each of the three enemy formations as they approached their targets on the 19th, and next day his whole air force delivered full- strength blows on the Japanese fleet. The enemy carriers had evi- dently planned to launch planes against the Fifth Fleet and then retire, leaving their fighters to escort the bombers to Guam airfields. From these strips torpedo bombers would then continue the attack. By the time the Japanese fleet retired to the west, it had lost nearly 400 aircraft and 14 ships. The demands of the Saipan battle delayed the attack on Guam and Tinian, and W Day for Guam was indefinitely postponed. The transports carrying the Southern Landing Force, which were cruising in the area east of the Marianas, were ordered to sail to Eniwetok on 25 June to await further instructions. On 30 June Admiral Conolly and General Geiger flew from Guadalcanal to Saipan to confer with Admiral Turner and General Smith. They decided to set 21 July as W Day; to attach the 77th Division to the III Amphibious Corps; to make one RCT of the 77th available on W Day, and the remainder of the division not later than W Day + 2. The change in W Day allowed time for transports to bring forward the 77th from Hawaii, reinforcing Southern Troops and Landing Force for the Guam attack. 11 GUAM 1 4 4 ° 4 5* 0 I g 3 4 S MILES 1 4 4 0 45' MAP NO. 4 12 The Island of Guam Guam, Japanese-held since December 1941, is the southernmost of the Marianas. Its area of 228 square miles, the largest in the Central Pacific between the Hawaiian Islands and the Philippines, is approximately equal to the total area of the other 14 islands in the 600-mile-long Marianas chain (Maps Nos. 4 and 27, page 12 and inside back cover). The extreme length, north to south, is about 34 miles; the width, east to west, varies from 5 to 9 miles. From a strategic standpoint Guam was important because it was large enough to become a principal forward staging area for further advance toward the Philippines and Japan. Apra Harbor, on the west coast north of the Orote Peninsula, provided safe anchorage deep enough to accommodate medium-sized vessels. The harbor also afforded landing and take-off lanes for seaplanes, which had been used by the Navy and Pan American Air Lines before December 1941. On land Guam had many sites for airfields suitable for the heaviest bombers. At least two fields built and used by the enemy were already in existence. One, a mile-long strip, was on Orote Peninsula; the other was east of Agana. In possession of United States forces, the island would be denied to the enemy as a refueling, supply, and aircraft staging area. Approaches to Guam present formidable obstacles to invading forces. Less than ten miles of the coast line are suitable for an amphibious assault, and these stretches only at higher stages of tide. Coral reefs, high cliffs, and heavy surf combine to deny most of the shore to landings in any force. The reef, continuous except for small breaks, fringes the entire island and fills many of the coastal bays. The greater portion of the reef ranges in width from 25 to 700 yards; to the southwest it extends toward Santa Rosa Reef for 21/2 miles. The lowest reefs are covered by a few feet of water at mid or high tide, allowing only boats of two-foot draft to pass over them. Reinforcing the reef barrier along all the northern shore are high cliffs, rising sheer from the reef shelf or the narrow beach to heights of 600 feet. In the Apra Harbor area only small groups of men could attempt the cliffs extending around the western tip of Orote Peninsula, where an occasional ladder, concrete steps, or narrow trail through a notch lead from the shore to the mainland. The rough waters on the southeast side of the island also prohibit a landing 13 in force; there are a few openings in the reef, but the heavy surf restricts approach through these narrow breaks. At no point would the landings be easy. The least hazardous beaches are in Agat Bay from Facpi Point to Haputo Point, and to the northeast from Asan Point to Adelup Point. Along both these stretches men could wade from the reef to the shore, if their landing craft could not pass the reef barrier. A further advantage was that neither stretch was blocked by a cliff. Their beaches are bordered by a coastal plain, a half mile to a mile in width, over which the men could push inland. Overlooking these beaches the terrain rises from the coastal plain to a range of hills which dominates the western shore of the southern half of the island. Peaks in this range, the key hills for control of the entire island, reach heights of more than a thousand feet about two miles inland. Mt. Alifan (869 feet) and Mt. Tenjo (1,022 feet) command the southernmost of the two beaches; Mt. Chachao (1,046 feet) and Mt. Alutom (1,082 feet) command the northern. On the east side, the range gradually slopes down to foothills and a plateau stretching to the coast 100 to 300 feet above sea level. Heights, primarily volcanic rock, are rugged and sparsely covered with tall, coarse, sharp-edged grass and scrub growth, except between Mt. Alifan and Mt. Lamlam (1,334 feet) where timber is found in large stands. Orote Peninsula and Cabras Island, on the west, and the coastal regions, on the east, are underlain by coral limestone. Here ravines and lower lands are heavily wooded and thick with tropical growth. Weeds, trailing vines, and tropical vegetation, con- sisting of strand trees intermingled with lianas, air plants, and under- scrub, grow to six or eight feet, and at such rate as to make even roads impassable if they are not used constantly. Rice paddies and coconut groves are cultivated in the marshes and lowlands. The topography of the northern half of the island differs markedly from that of the south. From Agana and Pago Bay a forested lime- stone plateau rises gradually to more than 600 feet at the northern end of the island. East of Agana, approach to the plateau is through an area of low hills, covered with palm trees. These hills merge into the plateau broken only by Mt. Barrigada (674 feet), Mt. Santa Rosa (870 feet), and Mt. Mataguac (600 feet). Four natural clearings exist in the forest, on Mt. Santa Rosa, Mt. Mataguac, at Finegayan, and near Pati Point; man-made clearings are restricted almost entirely to roads, limiting a military advance to the channels 14 BLUFFS RISING 600 FEET above the water make a barrier of the Guam coast. Because of cliffs, landing -points for large invading force were limited. The oblique above shows a two-mile stretch on Orote Peninsula. Below is a close-up of a rugged coastal section. of the existing road network. Because porous coral subsoil absorbs all rainfall, the section has no rivers. Pago River, northernmost of the island’s five streams on the east coast, flows from the foothills of Mt. Chachao to Port Pago. Tropical growth on the entire island thrives in the constant tem- peratures, with daily averages ranging throughout the year between 79° and 83° F. The rainfall is seasonal, with ranges from 15 inches a month upward. The summer monsoon period (July-October) is the wettest season, rainy days averaging 20 a month and the humidity staying near 90 percent or above. About 100 miles of hard-surfaced, two-lane motor road existed on the island in 1940. This type of Class A road, built of a kind of soft coral rock, ran from Agat northward along the coast through Agana and beyond Mt. Machanao. A section of it extended inland and across the island to Barrigada, Finegayan, and beyond Yigo. Some stretches of this road were safe for speeds of more than 40 miles per hour, but for heavy traffic every mile of surface would require constant maintenance. A network of Class B roads, of single- lane width with no surfacing, supplemented the Class A two-lane highway through most of north Guam. Except during heavy rains, these secondary routes were good for light, rapid traffic moving in one direction. From Agat to the south a Class B road joined a two-lane highway at Umatac, which skirted the island’s shore to Pago Bay and crossed the waist of the island to Agana. Travel through the interior of southern Guam depended largely upon trails, some wide enough for bull carts. Military movement through south Guam would be lim- ited almost entirely to the coastal two-lane highway. The status of these roads in 1941 was the latest information the invasion forces had; it seemed unlikely that the Japanese had under- taken the difficult task of extending or improving them. However, engineers estimated that in northern Guam they could cut at the rate of a mile an hour a route wide enough for transporting artillery pieces, to relieve the existing roads of some traffic. According to the 1940 census, there were about 22,290 permanent residents on Guam, more than half of whom lived in the main city of Agana. The remainder of the population lived in very small villages; only 8 towns, including Agana, had more than 500 inhabi- tants. Many of the natives, called Chamorros, are descendants of 16 the Spanish, Mexican, and Philippine soldiers who occupied the island after 1670, but others have American, British, Chinese, or Japanese forebears who came later and intermarried with the natives. Most of the Chamorros are Catholic, and almost all of them can speak some English. Although 80 percent engage in agriculture, their methods are so poor that the staples of their diet have to be imported. Evidence that the natives are loyal to the United States was their attempt to keep alive after December 1941 the six American survivors of the Japanese assault. The enemy discovered and killed all except George Ray Tweed, Radioman lc, whom the natives guarded for more than two years as a symbol of continued American sovereignty over Guam. Generally friendly and docile, they had grown increasingly restive under the Japanese, but the extent of their opposition before American invasion was not known. Japanese rule of Guam began after they overwhelmed the navy and marine garrison of 555 men, who put up what resistance they could. At the time, despite its importance to the United States, the island was not fortified. Defending marines -had only a few .30-caliber and .50-caliber machine guns and no mobile artillery to use against an enemy task force estimated at three cruisers, three destroyers, and a convoy of eight merchant ships. The Japanese took over the naval THE ENEMY TASK FORCE landed at Agana in December 1941 , ac- cording to this picture from an illustrated review of Japanese naval operations. The enemy force moved on the western coastal road to Cabras Island and Orote Peninsula, thus securing the entire harbor area. 1 ? ENEMY DISPOSITIONS ON GUAM JULY 1944 Q) 2d Battalion, 18th Infantry @ 48th Independent Mixed Brigade and port of 29th Division © Rest of 29th Division ® 5th Company, 38th Infantry © 54th Keibitai '© 38th Infantry © 10th Independent Mixed Regiment Contour interval 300 feet Turnon Bay I nor a j an Pago Bay Cobras / MAP NO. 5 18 installations in Apra Harbor, the storehouse and repair shops at Piti, and cable facilities and marine barracks at Sumay. They recruited slave labor from the natives to assist in maintaining their base. Enemy Forces on Guam Once before in our history American assault units had appeared off Guam, but then it had been comic opera. On 20 June 1898, shortly after the beginning of the Spanish War, the Charleston fired a few shots from its secondary battery on Fort Santiago as a pre- liminary to occupation. The Spaniards did not know of the opening of hostilities far to the east; legend on Guam even has it that they interpreted the gunfire as a friendly salute. At any rate, their only defense was four small guns of obsolete design, formerly used for saluting but at that time condemned as unsafe even for that purpose. The island was occupied without opposition by marines and by 2 companies of the 2d Oregon Infantry Regiment, taken to the shore by 25 rowers. No one expected comic opera in 1944. The experiences of Tarawa, Makin, Kwajalein, and Eniwetok had shown the ferocious quality of Japanese resistance. The strategic importance of Guam indicated the probability that the enemy garrison would be strong, and the island’s extensive land mass led the Central Pacific forces to expect a longer defense than that encountered in earlier operations. The fighting on Saipan did nothing to alter this estimate. After the invasion of Kwajalein the III Amphibious Corps C-2 learned that the Japanese were transferring army troops from Man- chukuo to Guam to reinforce the 54th Keibitai, nucleus of the naval units in complete charge of the island’s defense (Map No. 5). The reinforcing army units from China, organized under the South Marianas Area Group, arrived on Guam in March. The group in- cluded the 29th Division (with the 18th and 38th Infantry Regiments ) commanded by Lt. Gen. Takeshi Takashina, and the 6th Expeditionary Force. The force was composed of three infantry battalions, a field artillery battalion, and an engineer company of the 1st Division; and an infantry group headquarters, three infantry battalions, one moun- tain artillery battalion, and one engineer company of the 11th Divi- sion. In June the 6th Expeditionary Force was dissolved. The units of the 1st Division formed the 10th Independent Mixed Regiment 19 GENERAL TAKASHINA AND COLONEL SUENAGA inspect the defenses along Agat beach. The 38th Infantry, under Colonel Suenaga (at left), manned positions in the Agat area, later assigned to the Marine's 1st Provisional Brigade and to the Army's 77th Division. under Lt. Col. Ichiro Kataoka; those of the 11th Division became the 48th Independent Mixed Brigade under Maj. Gen. Kiyoshi Shigematsu. Before the invasion of Guam, III Amphibious Corps estimated that the total enemy strength on the -island was about 18,500, of which 13,000 were army troops and 5,500 naval. On 14 July intelligence officers of the 77th Division were inclined to revise their estimates of the number of Japanese troops on Guam upward to more than 36,000. Division’s higher figure, almost twice that of Corps’, was based partly on units identified on the island, and partly on the potential capacity of the enemy to land additional troops on Guam until 15 June. 20 Known locations of Japanese army and navy troops in June placed the 2d Battalion, 18th Infantry in northern Guam, the 48th Inde- pendent Mixed Brigade and part of the 29th Division in the Turnon Bay area, the rest of the 29th Division in the waist of the island between Agana and Pago Bay, the 54th Independent Guard Unit on the Orote Peninsula, the 38th Infantry, except for the 5th Company on Cabras Island, in the Agat sector, and the 10th Independent Mixed Regiment to the southeast. Because the whole of the Agat sector was relatively isolated by limited routes of communication from the more populated areas to the north, the 38th Infantry, defending it, was more or less independent of the rest of the island command. Although in June the enemy had stationed his forces to cover the entire island, during July he began to shift them to the areas most vulnerable to an attack from the sea. JAPANESE 200- MM COASTAL DEFENSE GUN, emplaced on Bangi Point in Agat Bay , is examined by III Corps men. Revetment, destroyed by pre-invasion bombardment , was never completed. Other revetments had protective roofing. This is one of two naval shore guns on the point. 21 Captured documents indicated that the enemy considered these areas to be along the central portion of the west side of the island, where the coastal features presented the least formidable barrier to an invading force. According to the chart of installations compiled by the III Amphibious Corps, the enemy in the sector from Agana to Agat Bay had about twenty-five 75-mm mountain guns, ten 70-mm to 90-mm howitzers, two 37-mm antitank guns, and more than thirty- five machine guns. These were supplemented by at least 25 naval coastal defense and dual-purpose guns. Rifle pits, trenches, and barbed wire added to the strength of the beach defenses, and mid- July studies indicated that the enemy was increasing their depth PREFERRED PLAN OF ATTACK ON GUAM m Amphibious Corps MAP NO. 6 22 daily. The Japanese were also believed to have a large amount of mobile artillery and some tanks to lend support to their fixed posi- tions along the shore. Planning staffs of III Amphibious Corps knew that the enemy's defense of the island would be favored by the reef and the hills overlooking the most likely landing beaches, and that enemy defenses in those areas might indicate the intention of fighting hard at the shore. They later learned that the Japanese commanders were ordered: "While the enemy is advancing from the line of coral reefs to the shore, the combined infantry and artillery fire power will be devel- oped. In particular when they reach the water obstacle, oblique and flanking fire will be employed to establish a dense fire net and thus annihilate them on the water." Plan of Attack The preferred plan for the assault phase of the operation on Guam, which the III Amphibious Corps had prepared in April and May, remained substantially unchanged after the capture of Saipan. The revisions, made possible by the postponement of W Day, increased the duration of the preparatory naval bombardment, strengthened Southern Troops and Landing Force, and provided for limited recon- naissance of the beaches prior to W Day. Although the plan for the assault phase was simple it demanded close cooperation of all arms. The attack was to develop simultane- ously on either flank of the military heart of the island, the Orote Peninsula, with its air strip, and Apra Harbor, with its installations (Map No. 6, page 22) . Because high cliffs and a strong enemy coastal defense made a frontal assault on the peninsula and the harbor im- possible, the plan involved landings north and south of Apra Harbor. From the north one force of the III Amphibious Corps was to drive toward the base of the peninsula and there meet the other force, which had meantime landed and approached from the south. The combined forces, having secured control of the hills commanding Orote, were to isolate and "pinch off” the peninsula from the rear. Beaches chosen for the landings lay within the two stretches of shore most favorable for an amphibious assault. On the northern stretch, the landing beaches were designated at Asan between Adelup Point and the Tatgua River. On the southern stretch, they were 23 designated in Agat Bay between Agat village and Bangi Point. Al- though these beaches were the easiest portions of the island to assault from the sea, they afforded limited routes of approach to the interior, especially to the southern part of the island. Troops moving from the beaches could use the highway running along the coast in either direction, but the mountainous regions in the south were accessible only by trails and a few miles of surfaced and dirt road. Using the limited routes from the beaches, the III Amphibious Corps was to secure a beachhead by seizing a final beachline on the ridge that commands both landing areas. The line was to extend from Adelup Point along Mt. Alutom, Mt. Tenjo, and Mt. Alifan 24 LANDING BEACHES between Agat village and Bangi Point are at foot of coastal range and are domi- nated by Mt. Alifan , seen on left. Water obstacles , similar to those in left foreground, are removed from area where boats shuttle from reef to shore. Photo taken W + 4. to Facpi Point. Once in control of a beachhead anchored on the final beachline, the corps would first attack Orote Peninsula from the east and then prepare to capture the rest of the island. Corps assigned the northern and most heavily defended sector to the 3d Marine Division, which would land on the beaches between Adelup Point and the mouth of the Tatgua River, advance to the south, and occupy the area lying east of Apra Harbor. As the marine division moved to the south, it was to secure and defend the final beachline in its sector. The 1st Provisional Marine Brigade was to land on the beaches between Agat village and Bangi Point and then turn north in a wheeling movement into the base of the 692437 °— 46— 3 25 MT. ALIFAN SLOPES MT TENJO MT. ALUTOM MT. CHACHAO 26 OROTE PENINSULA CABRAS ISLAND ASAN POINT i Ann up point HILLS IN WESTERN COASTAL RANGE, commanding Orote Penin- sula, rise a thousand feet above airfield and harbor areas. Mts. Cha- chao, Alutom, Tenjo, and Alifan are high points on final beachline, ob- jective of Assault Phase to "pinch off" Orote. Taken from 1,600 feet. 27 Orotc Peninsula. The 305th RCT of the 77th Division was chosen to support the brigade in this landing. The 2d Battalion with a platoon of the 706th Tank Battalion, boated in LCM's (Landing Craft, Mechanized), was to assemble between the launching area and the line of departure at H Hour + 120 ready to land on brigade order. The 1st and 3d Battalions were to debark and land whenever the brigade called them. Once ashore, the combat team was then to occupy and defend the final beachline while the brigade attacked up the peninsula. The rest of the 77th initially was to be in corps reserve. Two alternative plans were prepared by the corps, in case last- minute information disclosed that either of the beaches scheduled for landings under the preferred plan was too heavily defended or otherwise unsuitable. One of these provided for the entire invading force in echelon to go in over the beaches between Agat and Facpi Point, seizing Orote Peninsula and Apra Harbor, and overrunning the rest of the island from this beachhead. The other alternative plan was substantially the same as the preferred plan, except that the brigade would land between Bangi Point and Facpi Point instead of between Agat village and Bangi Point. However, the adoption of neither of these plans was necessary; the preferred plan was followed. W Day had been set for 21 July; H Hour was to be 0830. 28 Assault Phase Preparations for W Day AS THE OPERATIONS ON SAIPAN NEARED A CLOSE, air and surface forces of the Fifth Fleet began a systematic "softening” of enemy defenses on Guam. The original plan had called for only two days of preliminary naval bombardment, to take place on W — 2 and W — 1, but postponement of the attack on Guam made possible a much longer and heavier preparation, lasting 16 instead of 2 days. Naval air strikes began on 5 July. From then to 21 July planes from the Fast Carrier Task Force bombed and strafed the island daily. Three days before W Day the volume of air blows increased, reaching a peak on the 20th when the carrier planes made 6 14 strafing runs and dropped 486 tons of bombs on the already battered island. This series of blows neutralized Guam’s principal airfield, on Orote Peninsula. The preliminary air strikes were coordinated with naval gunfire. On 8 July four cruisers of Southern Attack Force led off with a 3-day bombardment, firing five thousand five hundred 5- and 8-inch shells on the coastal defenses. From the 12th through the 16th, four battleships fired more than three thousand 14- and 16-inch shells. During the next 4 days 3 battleships were joined by 2 others and by 6 cruisers, and they blasted the island with more than 16,000 shells. LCI(G)’s (Landing Craft, Infantry [Gunboat]), closing to within a few yards of the reef, raked trenches and pillboxes and reported the location of enemy positions to the heavier ships. De- stroyers screened the larger ships and delivered harassing fires at night. Admiral Conolly, directing the bombardment from the flag- ship, supervised the destruction of every known gun emplacement that would seriously endanger the assault landing. Meanwhile, during the 16 days of air and naval preparations, the III Amphibious Corps at Eniwetok waited for orders to return to 29 MAP NO. 7 the Marianas. While the troops waited, they had a chance to leave the cramped quarters of their transports for the first time in more than a month to exercise ashore on the limited atolls of the Mar- shalls. On 6 July General Smith attached the 77th Division to the corps. The 305th RCT left Oahu to join the force at Eniwetok as early as 1 July. The rest of the 77th Division sailed direct from Oahu to Guam. The corps, including the 305th RCT, moved from Eniwetok on 18 July aboard the transports of the Southern Attack Force to arrive off Guam the morning of W Day, 21 July. En route the troops went through final, exhaustive briefings. They pored over tactical maps for details of the landing beaches, roads, 30 towns, and enemy installations. They studied the terrain models of the island, showing graphically the natural characteristics of the shore and the hilly, wooded inland. As the transports neared the objective, the men gave their weapons a last check and prepared to disembark. The Landings The bombardment on W Day opened at 0530 when thunder of 1 6-inch guns of the Southern Attack Force offshore at Guam broke the early morning quiet. Between the heavy salvos from battleships, sharper reports of 5-, 6-, and 8-inch guns echoed across the island’s western beaches into the mountains above. Six battleships, four heavy cruisers, five light cruisers, and seven destroyers moved slowly along, their guns trained on the dark bulk of the land mass. Bursts of flame lit up the dawn as shells exploded on the beaches and in the hills behind. At 0803 the slow, deliberate shelling of coastal installations and bivouac areas stopped, and the ships turned their guns to intensify the fire on the beaches. At the same time, carrier planes, flying above the naval gunfire trajectories, dropped depth charges along the shore and strafed the landing areas. Under this air and naval protection, LVT’s (Landing Vehicles, Tracked), packed with the first wave of marine assault units, assembled in position on a quiet sea several thousand yards from the Asan and Agat beaches and on signal crossed the line of departure for the shore. Eight minutes before H Hour, naval guns bearing on the landing beaches speeded up their volleys. All 5-inch guns began firing at the rate of ten rounds per gun per minute, and 6- and 8-inch guns also increased their rate of fire. Forty-eight carrier-based fighters and bombers strafed and bombed the beaches. When the first wave of marines was 1,000 yards from the beach, hundreds of rockets, fired from LCI(G) ’s, hit the shore with terrific impact. The LVT’s crawled over the reef and waded through the two feet of high water toward the beaches. 1 When the men were 300 yards offshore, the fire lifted and concentrated on the flanks and rear of the beaches. The planes shifted their attack farther inland. ’High tide in the morning of 21 July was at 0712. Its height at 0833 was 2.4 feet. 31 THE FIRST WAVE OF LANDING CRAFT heads for Agat beaches. Smoke from targets , hit by air and naval bombardment preceding the invasion , rises along shore. Orote airfield, an objective of marine brigade , is seen at top left. ( Photograph taken from 5,000 feet.j The first wave of the 3d Marine Division hit the Asan beach at 0828, and three minutes later the leading wave of the 1st Provisional Marine Brigade landed at Agat (Map No. 7, page 30) . The bombard- ment had knocked out virtually all the enemy positions on the beaches, but a few Japanese machine gunners fired from caves near the water’s edge before being overcome. Emplaced in the hills commanding the beaches, enemy mortars and artillery put fire on the troops. Air strikes silenced some of this fire against the 3d Division. At Agat, where the enemy had mined the reefs and the beaches, the 1st Brigade’s landing was more difficult. Enemy guns on Gaan and Bangi Points sank 20 LVT’s; dukws bogged down in the silt on the reef. However, by 0900, 30 minutes after H Hour, tanks were ashore and in action. As the troops of the 1st Provisional Marine Brigade pushed inland, they came under more fire from mortars and artillery. They held off 32 two small, spirited enemy counterattacks, which indicated that the Japanese might be able to attack when the Americans had committed sufficient forces to make the effort worthwhile. Nevertheless, by eve- ning of W Day the marines had penetrated inland 2,000 yards on a 4,500-yard front. For support in holding this beachhead against an expected counterattack that night and in expanding the area the following day, the brigade had summoned during the afternoon the 305th RCT of the 77th Division, commanded by Col. Vincent J. Tanzola. The 2d Battalion, Lt. Col. Robert D. Adair commanding, was first on call. It had debarked from the transport into landing craft during the opening hour of assault; then the battalion waited, circling in the assembly area. Since the marine brigade was meeting only moderate opposition at the start, the 2d Battalion was not summoned to shore SMALL BOATS LEAVE ASAN BEACHES for men and supplies. On W Day Id Marines start an eight-day battle for hills dominating shore. until 1300. When they reached the reef, there were no LVT's to pick the troops up and carry them in. They waded ashore in water waist- deep, 1 falling into occasional submerged shell craters. In order to avoid these and keep their weapons dry, the 2d Battalion men tended to bunch on the axis of a narrow channel where the footing was good. Fortunately, though the beach area was open to the fire of enemy guns, the Japanese were fully occupied by the marines, now pushing forward a half mile inland. The 2d Battalion received little fire. 1 The average rifleman carried a steel helmet and liner, gas mask, life belt, rifle, bayonet, grenade launcher, and light pack. He also had two bandoleers of ammuni- tion slung around his chest, a bag full of rifle grenades hung from his neck, a pouch of hand grenades strapped to his thighs, a two-foot long pair of wire cutters tied to his pack, two canteens of water, first aid pack, and a machete hanging from his cartridge belt. Heavy weapons company men had to carry most of this equipment plus part of a mortar or heavy machine gun. "Have you dubbed your shoes?” they asked one another as they pushed through the deep water. 34 WAITING FOR ORDERS to land at A gat beach. The 105 th RCT, sup- porting the brigade on W Day , de- barked from transport to Coast Guard- manned landing craft before H How and circled outside the reef until Brigade called for reinforcements to hold beachhead during night. The remainder of the 305th had even greater difficulties in making shore and was even more lucky in that enemy fire did not take advan- tage of the situation. Colonel Tanzola received orders, at 1530, to land his other two battalions at 1530, the message having been delayed an hour in transit. He had only enough craft to land one battalion, pending return of the 2d Battalion’s craft, and so informed Brigade. The 1st Battalion, commanded by Lt. Col. James E. Landrum, de- barked at 1615, then was held up by naval boat control officers who said they had no instructions to allow movement toward shore at that time. It was 1730 before Brigade settled this issue. Darkness was now close at hand, and Colonel Tanzola suggested that unloading be suspended. Brigade ordered the movement to proceed. Some slip- up had occurred in coordination or communication between Brigade and the Navy, and naval control officers had not called for the LVT’s at the reef. The men waded in, this time in higher water, and were 35 MAP NO. 8 often forced to swim past the deeper holes. By the time they reached the beach, the units were intermingled and thoroughly lost in the dark- ness. Colonel Landrum found they had veered several hundred yards south of their planned touchdown and were dangerously near enemy held territory. With staff officers and guides, he found the assembly area, and managed to get most of his battalion there by 2130. The 3d Battalion, commanded by Lt. Col. Edward Chalgren, Jr., was waiting for the return of craft that had taken in the 2d, and these were delayed in getting back. The transport was suddenly ordered out to sea because of a report of enemy submarine attack. It steamed out 10 or 15 miles, then came in again, arriving at 2120. Debarkation finally commenced, though some craft were still missing. As a result of the darkness and lack of craft, the whole movement was delayed, 36 and the 3d Battalion did not reach the reef until 0330 on W + 1, some of the craft scattered far south of the rest. Fearing that they might draw fire from friendly troops if they moved inland, the dis- organized units dug in on the beach for the night. Some elements did not get to dry land until 0600. The 305th had had its first lesson in the liability of all plans (and particularly in landings) to upset by reason of "changing situations" and "unforeseen developments. The assault troops had established precarious footholds at Asan and at Agat, near both ends of the final beachline. Neither the 3d Marine Division nor the 1st Provisional Marine Brigade had reached the beach- line in its zone. Both holds on the island, each about two miles wide and one mile deep, were vulnerable to counterattack from higher ground. Over the left flank of the 3d Division and both flanks of the 1st Brigade, Mt. Chachao and Mt. Alifan towered from 300 to 500 feet above the highest ground within the beachheads. Expanding the Beachheads On W + 1, before the Japanese could strengthen their forces to the rear of the landing areas, the III Amphibious Corps was to secure both of its beachheads by reaching the high ground on the final beach- line. In front of the 3d Division, Mt. Chachao was the northernmost commanding height, and it lay about 3,000 yards from the unit’s forward positions. The 1st Brigade, with the 305th RCT attached, had to push inland only one-third of this distance to reach the top of Mt. Alifan, the highest point to the east of the Agat beach. The rest of the 77th Division, in corps reserve, was approaching Agat Bay aboard 12 transports and 2 LST’s (Landing Ship, Tank), ready to reinforce the marines on either beachhead. Until daylight the corps troops were harassed by small-scale but determined counterattacks. Shortly after midnight mortar and artillery fire became so heavy that the 3d Division suspended unloading activi- ties on Asan beach. At dawn the enemy launched an attack against the division’s left flank from Agana and the hills behind Chonito Clift (Map No. 8, page 36). The marines on the main defensive line, with tank, carrier-plane, and naval fire support, turned the enemy back. Meanwhile, Japanese forces east of Agat attacked the right flank of the 1st Provisional Marine Brigade. Aided by tanks and artillery the enemy soldiers fought their way through the brigade’s positions, and 37 MAP NO. 9 a few infiltrated as far as the perimeters of the 305th RCT. The ma- rines counterattacked, destroying five tanks and driving the enemy off. During the day the corps’ progress was slow. The 3d Division made very little gain toward the high ground on the final beachline. Enemy opposition on the left and center of the beachhead was so strong that the marines’ advance was held at a standstill except south of Asan. There they pushed 1,000 yards toward Mt. Chachao. On its right flank the division captured Piti Navy Yard, and one bat- talion landing team, executing a shore-to-shore movement, seized part of Cabras Island, north of Apra Harbor, which was not strongly defended except by aerial bombs emplaced as land mines. The 1st Brigade continued to push up the sparsely covered slopes of Mt. Alifan, climbing in the open under fire from the Japanese positions concealed by thick wood on the top. In support of this direct advance toward the summit of Mt. Alifan, the 305th RCT cut north to reach the ridge running northeast from Alifan and to secure the high ground above Road Junction 370. By 1700 the brigade and the combat team were on their objectives and had control of more than 3,000 yards of the final beachline. While the corps troops were attempting to secure their beach- heads on 22 July, General Geiger issued an order for the relief of the 1st Provisional Marine Brigade, to enable that unit to reorganize and get into position for the attack on Orote Peninsula. The de- fense of the beachhead from Inalas southwest to the coast near Magpo would be taken over by two RCT’s of the 77th Division, including the 305th RCT, which would revert to the division when the relief of the brigade was effected (Map No. 9, page 38). While the 77th protected the corps’ southern flank, the brigade was to prepare to capture Orote Peninsula. One RCT of the 77th was to remain afloat in corps reserve until ordered to land. The 306th RCT was designated by the division to take over the southern sector held by the marine brigade. A party headed by Col. Douglas C. McNair, Chief of Staff, and including Col. Aubrey D. Smith of the 306th Infantry and his battalion commanders with their staffs, went ashore on the 22d to reconnoiter the area and coordinate plans with the brigade. Shortly before noon next day the 306th began landing at Agat. 1 The 3d Battalion, commanded by Lt. Col. Gordon T. Kimbrell, reached its position between Mt. Alifan and Taene, and the 1st and 2d Battalions, under Lt. Col. Joseph A. Remus and Lt. Col. Charles F. Greene, respectively, went into assembly areas near the beach. 1 The unloading itself was a difficult operation. As a reserve division, the 77th had no LVT's. Assault divisions normally have two battalions. There were 60 dukws but these had to be reserved for cargo and to get the light artillery ashore. Consequently, plans had to be made to carry troops to the reef in landing craft, after which they would wade ashore at low tide carrying all equipment. Vehicles were to be dragged from the reef to the beach by bulldozers. The Division G-4, operating from an SC1319 (Submarine Chaser) just off the reef, was to coordinate all landings. Although the troops got ashore without difficulty, most of the vehicles drowned out in the water between the reef and beach, and practically all vehicles’ radio sets, even the water- proofed, were completely ruined. One medium tank dropped in a large pot hole and disappeared from sight. 39 306TH RCT COMES ASHORE on XV + 2. Soldiers uade to land from landing craft at the reef’ s edge. The men file along a shallow channel where they can keep their weapons above water. Amphibious vehicles , at right , continue unloading supplies. Third tractor in line tows a jeep. Relief of the 1st Brigade continued during the morning of 24 July. At 0800 the 306th assumed responsibility for the sector, and at 1400 the last elements of its 2d Battalion were in position. Action during the day consisted principally of skirmishing with enemy patrols and cleaning out caves and dugouts within the sector. During the early hours of darkness the enemy attempted to infiltrate through the lines, but he was driven off without casualties to the 306th. The 305th RCT had in the meanwhile extended its area north of the 306th sector. Within the line from Adotgan Point to Inalas on the final beachline, the 305th was holding all the ground to the east of Old Agat Road. Behind these forward regiments, the 307th, commanded by Col. Stephen S. Hamilton, and division troops were brought ashore and supplies were being built up on the beaches. The brigade, now grouped at the base of Orote, defended only enough space in which to prepare for the attack on the peninsula. 40 Attack on Orote Peninsula Extension of the beachheads during 23 and 24 July gave the corps necessary room for continuing the assault phase. The 3d Marine Division, completing the occupation of Cabras Island, had gained command of the north side of the harbor and, on the left flank, had fought up the steep slopes near Chonito Cliff. Although the marines in this sector had made slow progress, they had withstood an enemy counterattack of battalion strength, and were in position to press the advance toward the high ground along the final beachline. At Agat the 77th Division controlled a sector that was being developed as a staging area for the attack on the rear of the enemy’s main defenses protecting the Orote air strip and Apra Harbor. On 24 July General Geiger ordered a corps attack for 25 July, designed to complete the assault phase. This involved linking the northern and southern beachheads on the final beachline, and cap- turing Orote Peninsula. The main burden in this operation would fall on the marine units. The 1st Provisional Marine Brigade re- ceived the assignment of advancing into Orote Peninsula. To the north the 3d Division was ordered to reach the final beachline and, by extending southward, to pinch off the area east of Orote. Corps Artillery was to support the coordinated effort, giving priority to re- quests from the brigade, and the artillery of the 3d and 77th Divisions would also be ready to assist the attack on Orote. The 77th Division had the mission of holding its present lines in the southern beach- head; the 307th RCT, ashore at Agat, remained in corps reserve. Six hours after issuing the order, General Geiger postponed the time of jump-off for the Orote attack until 0700 on 26 July. The brigade needed an extra day in which to prepare for the assault and develop the enemy position at the base of Orote Peninsula. The supporting efforts by the rest of the corps proceeded as originally ordered. The 77th Division started to consolidate its line, while the 3d Division pressed toward the high ground on its front. At daybreak on 26 July the 77th Division artillery, commanded by Brig. Gen. Isaac Spalding, opened the attack on the Orote de- fenses. Although some of the batteries were not yet in position, the 305th, 306th, and 902d Field Artillery Battalions, under Lt. Col. Edward B. Leever, Lt. Col. Jackson P. Serfas, and Lt. Col. Leo B. Burkett, respectively, joined in the opening concentrations. Altogether 692437 ° — 46 — 4 41 OROTE PENINSULA 1st Provisional Marine Brigade 25-29 JULY 1944 IOOO 0 I YARDS MILE Note 28 July positions are approximate. A P R A HA R BOR MAP NO. 10 seven battalions of artillery, including those of the corps and the 3d Division, took part in the bombardment. Some batteries fired two rounds of preparatory fire per minute until the start of the brigade’s infantry assault. Naval support units, planes, and 90-mm guns of the defense battalion established on Cabras Island were employed in an effort to break the Orote defenses. The 1st Provisional Marine Brigade jumped off on schedule. Dense undergrowth and jungle at the base of the peninsula slowed its progress, and many Japanese had survived the bombardment to resist with mortars, machine guns, and small arms. The narrow 42 peninsula restricted deployment of the brigade’s forces, especially at the base where the land was only three-quarters of a mile wide, but by evening the troops had pushed 1,500 yards from the jump-off position and were more than halfway to the eastern end of the air strip (Map No. 10, page 42). Advances the next day, beginning at 0715, resulted in a dangerous alignment of the 1st Brigade’s forward units. While the 22d Marine Regiment, on the right, was meeting light resistance along the ap- proaches to the air strip, the 4th Marines had come up against pre- pared enemy positions in pillboxes and dugouts. The regiment’s assault elements, suffering heavy casualties from mortars, machine guns, and grenades, were pinned down. On the right flank, however, the men of the 22d Marines had advanced so steadily that by 28 July they were more than 600 yards ahead of the 4th Regiment. Their left flank was exposed to enemy counterattack. CLOSE-IN FIGHTING on Orote Peninsula. Infantrymen stand by in support while tank puts point-blank fire on concrete shelter near Orote airfield. The brigade called for army tanks on 28 July when the marines reached the airfield defenses, the strongest on the peninsula. OROTE AIR STRIP was captured on 29 July by marines with army tank support. A pier at Sumay in Apr a Harbor is seen in background. To give more support to the 4th Regiment, General Shepherd, commander of the brigade, called for medium tanks from the 77th Division. But only light tanks of the division’s 706th Tank Battalion, under Lt. Col. Charles W. Stokes, had landed, and some of these had been damaged in coming ashore. A platoon of five light tanks was quickly organized from elements of three units of Company D and dispatched under 2d Lt. Charles J. Fuchs. After reporting to the 1st Brigade early in the afternoon of 28 July, the platoon was sent to the 4th Marine’s sector. An attack was scheduled for 1600; in the meantime the marine infantry was consolidating its position. Two platoons of the brigade’s medium tanks, which had been shifted 44 from the 22d Regiment’s sector, had reinforced the flank units. Company D's platoon, joined just before the attack by two medium tanks from Headquarters Company of the 706th, was to strengthen the center of the line. At 1600 the light tanks of Company D moved through the 4th Regiment against the defenses that had slowed the marines. The tanks advanced cautiously over shell-torn terrain, and in a part of the zone each tank covered 50 yards of the front. Fighting was so concentrated that most of the tank fire was directed at positions within 10 or 15 yards of the tanks. At that range the 37-mm gunfire, often sighted through crevices in log structures, was effective even against enemy positions reinforced with tin sheeting, rocks, and brush. Infantrymen followed the tanks closely, mopping up positions and grenading Japanese in their fox holes. They also guarded the tanks so that the enemy could not close in with grenades. The Japanese weakened in the face of combined operations of the infantry and tanks. Within two hours after the attack started the forward elements of the 4th Regiment were abreast of the 22d Marines on the right. In restoring the brigade's front line the tank platoon of Company D had fired about 10.000 rounds of .30-caliber ammunition, 100 rounds of high explosive, and 20 rounds of canister. The light tanks alone destroyed 4 pillboxes, numerous dugouts, and approximately 250 Japanese. At the cost of a few casualties the 1st Brigade, supported bv the marine and army tanks, had cleaned out the area on the left and now held a line stretching across the penin- sula around the eastern end of the air strip. At 1000 on 29 July the brigade, again supported by tanks, con- tinued the attack on Orote and pushed across the air strip to the tip of the peninsula, about two miles to the west. The hardest fight- ing was for the mile-long strip, which the Japanese defended with small arms and mortars and where they chose to die in dugouts, pillboxes, and even a hangar rather than surrender. Less than five hours after the attack began, the marines had reached the western end of the air strip. Without stopping they pushed down the jungle trails to the ocean. At 1700, when the peninsula was completely taken, Company D, 706th Tank Battalion was relieved. In 4 days the brigade had killed between 2,000 and 3,000 Japanese defenders on Orote and had gained possession of the peninsula, with its harbor and airfield, extending 4 miles westward from the mainland. 45 iD MARINE DIV> A /MTChochoo^ Sumay ^Cota! 77TH DIVISION 1 THE GAP 77TH DIVISION AND 3d MARINE DIVISION 25-27 JULY 1944 Mwvw t Northern and Southern Beachheads. 25 xx 77 th Division Bounoary for 28 July (7 +) 77th Division Objectives for 28 July — — FBL— — Final Beach Line Facp! Point CONTOUR INTERVAL IOO FEET MILE TAROS MAP NO. 11 46 Establishment of Final Beachline In the corps attack that began on 25 July, the 3d Marine Division had been given the mission of reaching the final beachline in its sector and making a juncture to the south with the 77th Division, thus sealing off the Orote area and protecting the rear of the 1st Marine Brigade as it drove into the peninsula. A 4-mile gap sepa- rated the 3d and 77th Divisions on 25 July, and the enemy still held Mt. Chachao, the key high ground in the northern zone (May No. 11, page 46). Japanese resistance on this front had been stub born since the opening day, and the 3d Division had been slowed both by frequent enemy counterattacks and by the necessity of taking individual positions in frontal assaults that demanded use of flame- throwers, demolitions, and tanks. Heavy opposition continued to meet the 3d Division’s efforts on 25-26 July. On the 26th the division had to deal with a counter- attack in force by units identified as the 18th Regiment and elements of the 48th Independent Mixed Brigade. Next day the marines ex- tended their lines 1,500 yards on the right flank and 200 yards across Chonito cliff on the left. But in the center, forward marine positions showed little change from W + 1, and were still 2,000 yards short of Mt. Chachao. On 27 July the 77th Division, at General Bruce’s request, was ordered to take part in the effort to link the beachheads, east of Orote, by attacking to the north. The 77th was to extend its hold two miles and a half northward, leaving the 3d Division less than two miles to cover in its advance. On the southern portion of the final beach- line the 77th’s sector was now to include the northern approaches to Mt. Tenjo. The division boundary established by this order fol- lowed the unsurfaced road and trail leading east from Old Agat Road through Agafan to the junction of the road from Mt. Tenjo to Mt. Chachao. The new assignment of the 77th involved occupying Mt. Tenjo, the highest point on the beachline in its wider sector. General Bruce ordered that the 305th Infantry, with not less than a company, recon- noiter the approaches to Tenjo to determine the enemy strength on the hill. The 2d Battalion of the 307th Infantry, commanded by Lt. Col. Charles F. Learner, would assemble in the rear of the 1st Bat- talion, 305th. If Mt. Tenjo were not occupied in strength, the 2d 47 Battalion, 307th, moving out from Inalas at 0700 on 28 July, was to seize and hold the mountain, including the end of the ridge south of the peak and two knobs to the north. The 1st Battalion, 305th, was to establish contact with the 2d Battalion, 307th, and hold the high ground from Inalas to the ridge north of Cotal. On order the 3d Battalion, 305th, was to send patrols north as far as the division boundary through the area west of Mt. Tenjo. When General Bruce issued his order, intelligence reported little activity on Tenjo, although Japanese prisoners of war had declared that a force of 3,000 was in the vicinity. AN ANTITANK CREW of the 305th RCT defends the final beachline , firing from its position on the coastal ridge overlooking Harmon Road. THE 2D BATTALION, 305TH RCT in bivouac west of Ait. Ah fan. The unit is engaged in bolding the ridge between A it. Alifan and Ait. Tenjo. Moving out from its nearby assembly area at dawn on 28 July, Company A, 305th Infantry, met almost no opposition and reached the top of Mt. Tenjo by 0830. Because enemy resistance on the way had amounted to little more than scattered sniper fire and the summit was not occupied, Company A remained on the hill until it was relieved by the 2d Battalion, 307th, at 1500 that afternoon. While holding the hill, Company A experienced one of the diffi- culties attendant upon air-ground coordination. Planes suddenly ap- peared and began to strafe and bomb the troops, who ran for what protection they could find on the bare slopes. When the planes were coming in for a second attack, Pfc. Benno Levi seized some signal panels and dashed into the open under fire to display them. As soon as the pilots saw the panels, the strafing ceased, and the men of Company A consolidated their position on the mountain. This same day saw the 3d Marine Division complete its hard task on the north, conquering Mt. Chachao and Mt. Alutom and securing the road running from Adelup Point to Mt. Tenjo. The division had also reached a junction with the 77th by an attack to the south 49 which involved use of the 3d Battalion, 307th, under Maj. John W. Lovell, attached to the marines from corps reserve. The 3d Battalion, 307th, and the 3d Battalion, 9th Marines, attacked abreast with the division boundary as their objective. Enemy opposition was light, and by 1800 army and marine units were on the boundary in contact with the 77th Division. By evening of 28 July, while the battle for Orote was nearing its close, the corps had pinched off the ground behind the peninsula. The capture of Mt. Tenjo by the 77th Division and of Mts. Chachao and Alutom by the 3d Marine Division secured the entire beachline and completely closed the gap that had existed between the divisions. Any enemy west of the beachline was trapped. For two days, while the 1st Brigade completed capture and mop- ping up of Orote Peninsula, the 3d and 77th Divisions consolidated positions on their final beachline. Since 24 July the 77th had been maintaining its front from the seashore, two and a quarter miles south of Agat, along the Alifan ridge to Inalas by sending out platoons of scouts 2,000 yards from the beachline. On the 28th, when the northern part of the beachline was established, the 3d and 77th Divisions initiated patrolling in that area. Reconnaissance platoons, threatening large-scale attacks, kept the enemy off balance and at the same time gathered information on his movements. They burned shacks and high grass to smoke out well-camouflaged pockets, and occasionally directed mortar and artil- lery fire. The patrols were so effective that the enemy did not launch a single attack in force during the daytime. The Japanese were quick, however, to detect this method of de- fense, and on several occasions they tried to ambush the patrols. On 29 July one of these ambushes put up a strong enough fight to force a patrol of the 77th Division to call for help. While searching out the ambush, one squad of scouts was pinned against the steep side of a ravine in which the enemy was hidden. Within a few seconds two men were killed and three others were wounded. A distress flare, shot up by the scouts, brought reinforcements from the 305th Regiment. The additional firepower of the regimental platoon freed the trapped squad, and the patrol worked its way back to the final beachline, leaving its dead behind. The next day 14 dead and 1 wounded Japanese were found in the center of the ravine. They had been amply supplied and well dug in. 50 MEN OF COMPANY B of the 305th RCT on the high ground above Agat beach. Elements of this company, in defending final beachline , formed reconnaissance patrols that threatened enemy with large-scale attacks. Division patrols were active during the day, but they stayed within their lines at night, when the Japanese assumed the initiative. After dark infantry companies on the final beachline organized battalion perimeters on high points, arranging automatic fires to cover lower areas between the perimeters. Although fields of fire were cleared wherever possible and commanding ground was occupied, nearly every night small groups of the enemy employed skillful infiltration tactics to penetrate the line. The Japanese seemed to follow no standard plan for infiltration. They used a variety of weapons — mortars, small arms, sabers, and even hatchets. Sometimes the first evidence of the enemy was a grenade thrown into the perimeters; sometimes an enemy soldier in plain sight slowly walked toward the division’s lines; occasionally, heavy fire and grenades landed in the positions along the perimeter, and small enemy groups tried to move in where confusion had been 51 CRANES AT REEF’S EDGE transferred supplies from landing craft to LVT’s and dukws which could cross reef at any time regardless of the tide. The barge , being used as a platform for crane in this photo- graph , is preparing to load fuel on an Alligator. (Photo taken W + 4 ) created; in other cases enemy mortar fire preceded an infantry attack. But mortars were used less frequently at night than other weapons to pave the way for small groups attempting to harass the men or pass through the perimeters. During the first two nights the green 77th troops caused most of the confusion by their own movements and firing, but they soon grew battle-wise. The soldiers learned to stay immobile in their slit trenches, never venturing outside even if they had diarrhea. In order to reduce the enemy’s chances of discovering their positions, they learned also to hold their fire until they had a definite target. Trip flares that illuminated the whole area when set off by an infiltrating group were employed successfully and trapped a few Japanese. Patrolling during the day and organizing perimeters at night, the 3d and 77th Division held the corps’ final beachline until the com- pletion of the attack on Orote. With that accomplished, operations 52 of the assault phase ended. The corps, during this 10-day phase, had gained Apra Harbor, which was found to be in excellent condition, and Orote airfield, which was already being used for emergency landings. The assault operations had cost the III Amphibious Corps 5,987 casualties, mostly in the marine units. Of this number 958 were killed, 4,739 wounded, and 290 missing. The 77th Division, engaged in holding its sector of the final beachline, lost 217 men. Battle of Supply The reef that had kept the landing craft of the assault troops from getting to the shore was also a barrier to the supply boats, no matter how high the tide. However, III Amphibious Corps had planned on transferring supplies at the reef’s edge to smaller vehicles and had carried equipment for mooring ponton barges and causeways off the reef. Twenty-five light cranes, mounted on the barges, were to be used to transfer cargo from the LCVP’s (Landing Craft, Vehicle, Personnel) and LCM’s to dukws and LVT’s, which in turn would carry the cargo across the reef to the beach. LST’s were to beach against the reef, drop their ramps, and be unloaded by dukws and LVT’s. At first supplies were loaded into LVT’s and dukws in the transport area. During the first few days, the dukws moved cargo from the ships directly to dumps inland. After the beaches were secure, the plans for direct transfer of supplies from LST’s to dukws and LVT’s at the reef’s edge were put into effect. Numerous other expedients were used to get the 77th’s supplies ashore. The division borrowed cranes, ponton barges, and LVT’s from marine and navy units. Supplies were even floated ashore on life rafts from transports and on 10-man rubber boats which had been brought along for the use of the Reconnaissance Troop. The 60 dukws of the division were pooled and operated under G— 4 control. An officer on each of the six crane barges used by the division supervised operations with walkie-talkie radio communication ashore. The 77th Division com- mand or regimental commands ordered certain supplies or equipment from supply officers; shore personnel informed the officers on the crane barges of the desired cargo, and these officers in turn directed that cargo ashore to the requested area. 53 / BULLDOZERS CLEARED ROADS to beach dumps for the tracked amphibious vehicles which carried the supplies from the reef to storage and dispersal areas on shore. Along the reef fat center) a crane loads a tractor; the transport ships are anchored farther out to sea. Unloading was not accomplished without difficulties. Jeeps and other vehicles driven ashore drowned out even at low tide. The dumps, selected before the landing from maps and photographs, were limited in area, and many were located on marshy lowland where little satisfactory storage space existed. Tropical rains and constant grinding traffic produced a sea of mud on the roads to the dumps. Tracked movers sometimes took 3 hours to make a round trip from the beach to the dumps — a distance in most cases of only 6 00 yards. Wheeled vehicles repeatedly bogged down and had to be towed out by tractors. To keep beach roads and dump areas in operating condition, some of the shore party had to be diverted from unloading and storing supplies. Because of these conditions it became clear fairly early that the ships of the 77th Division could not be unloaded on a dawn-to-dark basis 54 only. Fortunately, since the enemy seemed unable to produce air support or to lay artillery fire on the beaches, it was possible to illuminate the beaches at night. Floodlights powered by generator units of the shore parties enabled work to proceed on a 24-hour basis. This expedient enabled the APA’s (Transport, Attack) to be 80 percent unloaded by the end of the fifth day. Landing supplies on this 24-hour basis imposed a tremendous strain on men and equipment. Of one group of 20 dukws working on Agat beach, 6 were out of commission at the end of the first day of unloading operations (chiefly from bent screws, damaged rudders, bent propeller shafts, and burned-out propeller shaft bearings), 2 more the following day, and 6 more on the next. The men worked with little rest or sleep; their food consisted of the regular combat rations. SUPPLYING THE 77TH DIVISION over "the toughest reef in this war" was a major operation. Photo shows the severe strain on equipment. RCT's operated the dumps until 24 July. On Agat beach the Corps Service Group, which had landed on 23 July, relieved the brigade of supply responsibilities. The brigade had maintained the 77th Division on marine stock for three days. On W + 7, after a week of clear weather and calm, the 3d Marine Division and the 1st Provisional Marine Brigade had all their supplies ashore. The 77th Division completed its unloading on W+ 10, except for two com- mercially packed ships. By the time the assault phase was over, the units had ashore an adequate store of materiel. 1 Food, clothing and equipment, fuels and lubricants (Classes I, II, and III) were available in amounts sufficient for 20-days’ supply. Only hard work and numerous field expedients had kept supply on schedule for the battles ahead. A naval officer, veteran of Guadalcanal, Attu, Tarawa, Kwajalein, and Saipan wrote to General Bruce, "Your people landed and supplied themselves over the toughest reef yet worked by any outfit in this war.” 1 Of the five classes of supplies for the 77th Division, Class I was initially of most importance. The "10-in-l” ration pack, seven days’ type "C,” three days’ type "K,” twenty days’ supply of ration accessories, and other special types were landed. Water was carried on transports at the level of two gallons per man per day, making a total of 190,000 gallons for the division carried in 5-gallon and 55-gallon drums. Most of this supply was brought ashore, but the early establishment of distillation units on the beach enabled the 77th to keep some of its water in reserve. Clothing and equipment made up Class II materiel. Clothing alone amounted to tremendous bulk because the division was required to earn’ impregnated protective clothing for all its men. The division developed a standard roll in an attempt to supply the troops without having to segregate rolls by companies and individuals. However, owing to transportation difficulties these were never delivered to the troops. This roll consisted of a shelter half, one blanket, mosquito bar, one "K" ration, cake of salt water soap, pack carrier, tent pole, five pins, a pair of mosquito gloves, and a waterproof clothing bag. Class III supplies were packed in 5-gallon and 55-gallon containers, and in 55-pound pails for heavy gear lubricants. It was necessary to carry' aviation gasoline for the liaison planes; leaded gasoline and diesel oil for trucks, tractors, and tanks; white gasoline for kitchens; and a variety' of weights of engine oils and gear lubricants. Class IV supplies consisted mainly of engineer and chemical warfare equipment. Approximately 225 tons of engineer items were carried, including fortification materials such as barbed wire, pickets, and sandbags. Heaviest of all were Class V supplies, loaded at the level of ten units of fire for antiaircraft weapons and seven units of fire for all others. The magnitude of this class of supplies can be seen from the fact that the 77th used 46,000 hand grenades alone in the operation. 5 6 Pursuit Phase Reconnaissance of Southern Guam AS THE OPERATIONS OF THE ASSAULT PHASE neared a close, the III Amphibious Corps started preparations for the next phase. By the morning of 28 July the capture of the main objec- tives on Guam — Orote airfield, Apra Harbor, and the high ground commanding them — seemed certain to take place within a day or two. However, there were convincing indications that the Japanese had not used up their means of resistance in the defense of this area. The corps had taken only 30 prisoners and killed 4,000 Japanese, about one-fifth of the estimated enemy strength on the island. Furthermore, the corps casualties, about 5,000, were half as many as the troops on Saipan had suffered in taking similar objectives, the Aslito air strip and its commanding heights. Evidently the Japanese were holding a considerable part of their strength in reserve for a stand in some other part of the island. The question before General Geiger was where this stand would be. He expected that the Japanese would group the bulk of their forces in northern Guam, where they could use heavy equipment. Any defense of the southern part of the island would necessarily be by small elements of infantry with light weapons; there were few roads to the inland regions and none of them were passable for motor traffic during the extremely rainy months of July and August (Map No. 4, page 12). In contrast, a good road network through- out the whole northern area would provide freedom of movement for large enemy units and their supplies. In addition the thick jungle and scrub growth on the limestone plateau would conceal their installations and their marches. Strongpoints on Mts. Barrigada, Santa Rosa, and Mataguac would command this part of the island. Because of these advantages of defense the enemy was believed to have set up supply dumps, fortifications, and emergency headquarters in northern Guam. 692437 ° 57 RECONNAISSANCE OF SOUTHERN GUAM 28 JULY - 2 AUGUST 1944 **