Chapter 12: Bloody Biak

When the Toem-Wakde campaign still was in the planning phase the instructions called for the 41st Division, less Persecution Task Force, to make a landing in the vicinity of Sarmi. As the plans took shape the Sarmi phase of the operation was abandoned in favor of a strike at Biak, one of the Schouten Islands. The initial phase of this operation was the landing at Arare on 17 May by the 163d Infantry while the decisive phase was to get under way on 27 May when the remainder of the Jungleers were to storm ashore on Biak.

The Schouten Islands are located in the north central portion of Geelvink Bay. Only a narrow channel separates Biak and Soepiori Islands, the two principal islands of the Schouten group. Biak is the easterly of the two and is the result of a series of regional uplifts of the earth’s crust which brought a shallow sea floor to the surface. A coral reef made an outside border around the island. The eastern third of the island, roughly the area east of an imaginary line between Sorido Village and Korim, is bounded by an almost unbroken ridge of this narrow, terraced, coral reef, which in places rises to 330 feet on the ocean side and 160 feet on the landward side. The reef is covered with tall rain forests and frequently is made up of parallel ridges which serve as additional obstacles in terrain already quite difficult. The island has a generally flat surface, with the exception of limestone mountains in the northwest and in a small area north of Bosnek.

A road suitable for motor transport was constructed by the Japs from Sorido Village to Bosnek. In addition to an excellent track running from Sorido Village to Korim, a network of trails radiates north and northeast from Bosnek. West from the surveyed airstrip site, north of Bosnek, run two trails paralleling the coral ridges. These trails assumed importance during the operation as the routes leading to Mokmer Airdrome.  Much thought was given to the selection of D-day for the Biak phase of the campaign. Those making the plans figured that if an interval of ten days separated the landing at Wakde and the assault on Biak, the amphibious shipping used at Wakde could supplement the shipping needed for the landing at Biak. Furthermore, such a spacing of the landings would enable fighter aircraft from Wakde to cover and support the operations at Biak.

Accurate maps were unavailable and headquarters  had to rely solely upon the reports of air observers and the interpretations of aerial photographs for the timely information of the terrain and the enemy installations in the objective areas. Although reconnaissance patrols could have obtained some helpful information these were not used because the detection of such activities by the Japs would have revealed the Allied intentions and robbed them of the ever important element of surprise.

Mokmer, Bosnek and the area between these two villages provided possible landing sites in the Biak area. The strongest resistance was expected at Mokmer, which was known to be the most heavily defended area. Aerial photographs indicated that between Mokmer and Bosnek either mangrove swamps lay immediately behind the beaches, or cliffs rose sharply from the beach. Bosnek finally was selected as the landing site because the area had a good road, two coral jetties and coral dispersal areas suitable for supply dumps.   The Biak force, known as Hurricane Task Force and commanded by General Fuller, had as its major combat unit the 41st Division, less the Wakde Force, reinforced. Hollandia was selected as the staging area for this force and under the palm trees and perfectly cloudless skies the preparations went on, beginning around 10 May. Work went far into the night in blacked-out tents which served as command posts. Yet, nearly everyone found a few lazy minutes each day to lie on the white sandy beach and swim in the blue surf. There were outdoor movies, and there were red alerts practically every night. One night it was necessary to sit in front of the theater screen for nearly five hours to see a particularly good show from beginning to end. Four red alerts interrupted the cameraman that night. Food was good and plentiful, and just before this force sailed for another invasion, a large group of men left the Division for the long-awaited voyage home via the rotation plan. These men were incredibly happy over having cheated combat—and possible death by so little as one week. And as it turned out they were more lucky than any realized because Biak proved to be the most expensive combat mission the Jungleers ever were to know—in length, arduousness and in lives lost.

During the planning phase the possible use of the 163d Combat Team as reinforcements for the Biak force was visualized. Accordingly, LCIs were to be available to transport this unit from Toem on 2 June.  In the event that the hostile opposition at Biak proved to be stronger than was expected, the 163d Infantry was the logical reinforcing unit since it would be moving from the nearest Allied base to Biak and would be strengthening its parent unit, the 41st Division. To insure the availability of the 163rd Regimental Combat Team for this role, without weakening the Wakde force, the 158th Combat Team moved from Finschhafen to the Toem area about 21 May.

On 25 May Hurricane Task Force assembled on Hollandia’s White Beach 3 and that night jumped off for Biak’s coral offshore reefs, narrow, sandy beaches and high, narrow coral ridges with their many honeycombed caves in which the Japs took refuge. These were to cause the Jungleers a lot of trouble. Biak had three airdromes. Mokmer, the most important of these, had to be taken before the New Guinea campaign could be concluded.

The force traveled all that night and the next day and night and on the morning of 27 May it stood offshore at Biak. The Japs must have known this was coming. The island had been subjected to heavy aerial bombardment and no shadow of a doubt could have remained when the Navy moved its cruisers and destroyers in close to shore two weeks prior to D-day and began tossing tons of shells into the island at the rate of thirty rounds an hour, continuing this pace night and day. However, the Japs just crawled farther into their holes and were safe from the bursting shells.

The morning of D-day was a brilliant, clear, sunny day. A forty-minute naval barrage and air bombardment left smoke billowing against the sky. It became so dense that troops in the landing craft could not see the shore and the objective areas were hidden from sight beneath the pall of a slowly dissipating grey cloud. The Japs, for the most part, retreated to their underground installations and just waited.

The coral reefs offshore caused some confusion among the landing craft as they came in to make the landing. The narrow sandy beaches offered an insecure foothold. The 2d Battalion, 186th Infantry, in Buffaloes, amphibian troop and cargo carriers, was the  assault battalion, hitting the beaches at 0730. A section where two jetties projected into the water was selected for the landing of this battalion. The first wave of sixteen Buffaloes was divided into three groups. Eight craft were to go in between the jetties, with four on each flank. Because of a six-mile-an-hour westerly current and the limited visibility the entire 2d Battalion, first, second and third waves landed in the swampy area just west of Mandon and about two miles west of the proposed landing site.

The 3d Battalion of the 186th Regiment was assigned to take a position on the west end of the beachhead and the 2d Battalion was to take up a position on the right, but it landed far out on the left. The 2d Battalion proceeded inland without resistance until it reached the Bosnek-Mokmer coastal road where it quickly reorganized. By noon the 2d and 3d  Battalions reached their respective objectives and the 2d was receiving scattered resistance from the caves in the face of the ridge.

The 162d Infantry, which had been assigned the mission of seizing Mokmer airdrome, landed behind the 186th Regiment. Once ashore the 3d Battalion, which was in the lead, passed through the 186th Infantry and began the westward advance down the coastal road toward Parai. The 2d Battalion, less Company E, followed the 3d Battalion down the coastal road.

Time was valuable at this stage of the operation and some was lost while the units criss-crossed back and forth to join their proper organizations. Careful orientation of the men as to their mission and the tactical situation added to the ease with which the predicament was adjusted.

Supporting the infantry were the 205th and the 146th Field Artillery Battalions; the 121st Field Artillery of the 32d Division; and the 947th Field Artillery, a Sixth Army battalion of 155mm howitzers, which had been attached to the task force for this operation. Division Headquarters and Division Artillery Headquarters were among the initial units ashore on D-day. By midmorning the artillery was ashore and the guns were in position at Bosnek Village.

The 186th Infantry had extended the beachhead one mile to the east and west of Bosnek and patrols were active to the north, meeting only slight resistance.  Meanwhile, at a point about seven thousand yards west of Bosnek the coral ridge approaches to within forty or fifty yards of the coastline and at this point becomes a vertical coral and limestone cliff, forming a narrow defile. Here the advancing 162d Infantry encountered the first organized Jap resistance. The resistance was not being offered by a large force but due to the terrain advantage, the few enemy troops were able to hold up the Jungleers’ advance for several hours. American tanks were pressed into action and, supplemented by naval gun fire, finally dislodged the enemy.

While this battle was in progress Company E of the 2d Battalion, 162d Infantry, had landed and was moving inland across the ridge in an effort to reach the plateau. It reported that the series of ridges was so rough and vegetation so thick that rapid progress was impossible. This company was to have maintained a position either parallel with or echeloned to the right rear of the 3d Battalion. However, it was lagging far behind and was unable to hold the position. In order to sustain a more rapid rate of advance.  Company E was ordered to rejoin the 2d Battalion and reached its parent unit at about the time the defile had been cleared and the advance toward Mokmer drome continued. By the end of D-day the 162d Regiment occupied positions with the 3d Battalion about  midway between Parai and Mokmer Village, and the 2d Battalion and advance regimental CP was at Parai Jetty. The 1st Battalion, which had come ashore prepared to follow the 2d and 3d Battalions down the coastal road or to re-embark in amphibian craft and move to Parai Jetty in a flanking movement, was in the vicinity of Ibdi.

As dusk closed in on the Jungleers, enemy planes made a bombing and strafing run over the beachhead area, causing only slight damage. During the night Company I of the 186th Infantry was harassed by enemy reconnaissance patrols while Company B was attacked by an enemy patrol for one hour beginning at midnight. It was believed that this patrol was transported by barge from a point farther east as the muffled sound of motors was heard from that direction just prior to the attack.

The second day found the 162d Infantry advancing to Mokmer Village where strong hostile forces laid down heavy mortar and machine-gun fire from the dominating cliffs on the north flank. The coral ridge and cliff turned sharply north just east of Mokmer Village and widened into a coastal plateau. A sharp coral cliff approximately twenty feet high ran diagonally across the coastal corridor, forming a terrace. The enemy launched an attack here and drove a wedge to the coast, thus cutting off the leading elements of the regiment while the 2d Battalion was pinned down and was unable to get onto the terrace. The shoreline in this area was a vertical cliff varying from twenty to sixty feet in height. Small secondary growth covered the area and was thick enough to prevent good observation from the ground but open enough to allow excellent observation from above. The enemy occupied a very formidable position in the steep limestone ridge to the north of the 3d Battalion. This ridge afforded the enemy perfect observation of Allied movements, excellent cover and concealment in the vegetation, coral caves and crevices in the ridge so that opposing fires had little effect upon him, while he was able to cover the area with devastating fire.

The cut-off 3d Battalion was suffering heavy casualties and communication was difficult since all wire lines had been cut and all but one radio failed to function.  The position of the 3d Battalion forward elements was untenable, and further advance was impossible until the enemy on the ridge and in the face of the cliff could be dislodged either by action from the north or by naval fire from the seaward side. During the afternoon the 3d Battalion began a withdrawal but enemy pressure heightened to such an extent that this move was impossible. Lack of communications prevented laying a concentration of sufficient fire on the enemy to neutralize his fire. The 3d Battalion repulsed several attacks. For the first time in the long New Guinea campaign the Japs were employing tanks against the Americans.

Ammunition and medical supplies were running dangerously low and LVTs were used to bring in these critical items. These remained well out in the channel beyond the range of enemy weapons. When they came abreast of the 3d Battalion area they darted to the beach in a direct line, one coming in at a time, to a position at the base of the coastal cliff which offered cover from enemy fire. When the supplies were unloaded wounded men were loaded and evacuated.

As darkness approached, the artillery, air and naval units were able to neutralize the enemy fire sufficiently to permit the cut-off elements to withdraw by infiltrating along the beach. Four tanks of the 603d Tank Company joined in the fight and covered the withdrawal, which was completed by 1830. All equipment and wounded personnel were evacuated from the forward area. The 3d Battalion passed through the 2d Battalion and took up positions directly to its rear. Patrols from the 186th Infantry still were probing north and east from the beachhead and a Company G patrol was dispatched to Opiaref but met no enemy.

In his report to General Krueger, General Fuller announced the situation as “grave” and requested reinforcements to consist of the 163d Regimental Combat Team. The 163d Infantry, less one battalion, made arrangements to leave Wakde and the 503d Parachute Regiment moved from Oro Bay to Hollandia for subsequent employment at Biak should developments require its use.

On the third day the enemy continued his resistance with strong offensive action, launching three separate counterattacks from the west, supported by tanks. American medium tanks took up the fight and the first tank battle to be waged in the Pacific followed. Failing to reckon with American tanks, the Japs foolishly sent their armor down the road in a column, each tank rushing forward to replace the lead tank as it was knocked out of action. At the close of this historic tank engagement, seven Jap tanks lay completely destroyed on the beach while others had been severely crippled and withdrew. The enemy ground troops, however, continued their aggressive action and the 162d  suffered heavily, although by the end of the day it had killed some four hundred Japs and was able to withdraw to more favorable terrain. The Japs made a circling movement similar to the one of the previous day, and again the regiment was cut off temporarily.  Company B and Cannon Company, acting as a rifle company during this campaign, broke the enemy line with a successful counterattack.

By now it was apparent that no successful attack could be launched against the airdrome area until Allied forces controlled the high ground overlooking it, and had neutralized the enemy fire from the Mokmer pocket and the coastal corridor approaching it from the east. It was decided to withdraw toward Mandon and regain contact with the 186th Infantry to the east. Led by the tanks some of the unit infiltrated through the defile while the remainder employed amphibian craft to fall back. One platoon of Company D, 641st Tank Destroyer Battalion, was ordered to maintain supporting fire with its 4.2-inch mortars and at the completion of the mission to destroy the weapons and rejoin the regiment. By nightfall the withdrawal had been completed successfully.

To the east the 186th doughboys had been subjected to two air raids in the early morning hours. During patrol activities that day they found a motor road which connected Opiaref with the surveyed drome north of Bosnek.

Following the withdrawal in the 162d Infantry sector a new plan of attack was formulated. The incoming 163d Infantry was to take over the defense of the beachhead area, thus relieving the 186th Infantry, which then could divert its activities toward the airdrome site north of the coral ridges and Bosnek. When preparations were complete, the 186th, making the main effort, would launch an attack westward along the high plateau north of the ridges, putting the regiment in position for an assault on Mokmer drome from the northeast. At the same time the 186th was making this move it was planned to have the 162d advance west to the drome along a narrow strip of level ground, between the sea and the coral cliffs. In the vicinity of Parai, the base of these cliffs and the seashore almost merged and this terrain feature was referred to throughout the campaign as the Parai Defile.

For the next three days the 162d Infantry conducted intensive patrol activities to determine the enemy positions on the ridges to the north. It also consolidated its positions and reorganized its broken ranks. The artillery, mortars, planes and Navy shelled and strafed the area of Parai, Mokmer Airdrome and the ridges which hemmed the drome on three sides away from the sea. The enemy was making splendid use of the defensive qualities of the terrain and there was little doubt lingering in the minds of the Jungleers that the coming battles would be tougher than anything which the Division had encountered thus far. That the Jap felt that Biak was worth fighting and dying for was evident by the increasing number of low-level bombing attacks carried out during daylight hours. Harassing attacks at night also were becoming more numerous. The 162d patrols found that what was thought to be a single ridge was actually a series of seven sharp coral ridges, which apparently had been caused by an upheaval in the earth’s surface. This entire ridge arrangement was honeycombed with small caves, holes and crevices and, though there was practically no soil covering the coral, the area was covered with a dense growth of rain forest. Two native tracks crossed the ridges just east of Ibdi but the enemy had strong positions blocking both trails.

Patrolling continued in the 186th Infantry sector until 1 June when the newly planned attack was inaugurated. The 163d Regiment landed at Bosnek on this date and took over the defense of the beach area. Now after more than fifteen months of fighting and dying in the jungles at Papua, New Guinea and Dutch New Guinea, the 41st Division was  assembled as a fighting machine and was making a coordinated effort for the very first time. Upon being relieved, the 2d Battalion, 186th Infantry, moved to Opiaref and reduced the enemy resistance there. Later the 3d Battalion joined the 2d near the surveyed drome north of Bosnek and made last-minute preparations for a coordinated attack to the west. Five tanks and one platoon of the 116th Engineers moved into the area and the 121st Field Artillery was attached to the 186th Infantry for the westward move. The engineers completed repairs on the supply road leading west from Opiaref by late afternoon. At the same time the 2d Battalion, 162d Infantry, took to one of the trails leading across the ridges on its north flank, and the 163d Infantry was aiding in the movement of supplies in addition to its defensive duties.

In the early morning hours of 2 June the 186th Infantry was attacked by a force of unknown strength. Mortar lire and loud shouting preceded the attack which lasted four hours and featured considerable hand-to-hand combat with each side employing machetes, grenades, bayonets and a limited amount of small-arms fire. At daybreak the attackers began to withdraw while some of the more seriously wounded Nips either committed hara kiri or attempted to fight and were killed. No prisoners had been taken but 86 Japs and three men of the 3d Battalion had been killed.

At 0900 the 186th began to move westward along the inland plateau. It was a slow, tedious march, and maintaining a supply line, especially for water, was a major problem. The regiment was flanked by mountains on its right and by the cliffs, dropping away to the sea, on its left. The heat and humidity were intense.  Thick scrub growth, about twelve feet high, covered the area and shut off any breeze. Each soldier was allowed only one canteen of water, which was most insufficient. Troops caught rain water in ponchos and, in many cases, this prevented heat exhaustion.  Some attempt was made to haul water to the troops as engineers followed the doughboys with bulldozers, opening a road for vehicles. Enemy resistance was light and the 186th plodded steadily westward.

At the same time the 2d Battalion, 162d Infantry, kept reducing Japs along its route of march. Late in the afternoon this unit established contact and was attached to the 186th Infantry just northwest of Ibdi.  Antitank Company of the 162d, also acting as a rifle company, was given the mission of covering the line of communication for the 2d Battalion. The remainder of the 162d Infantry was stalemated as a result of the enemy roadblock on the coastal road in the defile area.  Company A, 163d Infantry, made a landing on Owi Island on 2 June but found no enemy. It then moved to Woendi Island and again was unopposed. Zeros strafed the beach area at Bosnek and inland and many were brought down by ack-ack fire. Air Force troops relieved Company A on Owi and Woendi Islands and the 3d Battalion of the 163d Infantry moved north Opiaref to guard the 186th supply line.

On 3 June the 186th and 162d Regiments resumed movement westward, the former continuing along the inland plateau route while the latter clung to the coastal road. The 162d had progressed 2,500 yards when intense hostile fire forced the 3d Battalion withdraw from the Parai Defile. The 186th encountered only occasional sniper fire and advanced some 3,500 yards during the day. Supply remained a difficult problem since a very inadequate trail was the only means available. The 121st Field Artillery had such difficulty moving over the route that it finally retired to the surveyed drome area. Maintaining contact was extremely difficult for the infantrymen since visibility was limited to about ten yards.

The engineers by this time had made a reconnaissance of Owi Island and reported that it was suitable for construction of an airstrip. As the Mokmer drome obviously could not be secured for some time, heavy engineer equipment was moved to Owi Island and work began at once on a new strip. It was reported on 4 June that a large enemy naval force was headed for Biak and had been sighted American planes. The force, according to reports, consisted of two battleships, eight cruisers, and a considerable number of destroyers. It was estimated that would reach Biak by 1630. Location of US Navy unit

was such that they would be unable to reach Biak before 1930. All artillery units except the 121st Battalion were ordered to prepare to fire two batteries seaward. Bulldozers and dump trucks assisted in digging gun pits and preparing revetments. Headquarters prepared to move on a moment’s notice and alternate wire systems were laid. At 1710 news came that the enemy task force was about 35 miles west of Manokowan and that a large force of B-24s and B-25s was on its way to attack. American naval units were approaching Biak, and by 1940 four cruisers and eleven destroyers steamed f u l l speed past the island on a westward course. The Jap force was reported to have turned northwest at Manokowan and lost contact with Allied airmen about three hundred miles west of Biak. This is the story as related in a journal entry but it does not record the many little things that contributed to the excitement and trepidation felt by the men that day.

It does not record the fact that the day was very hot, and that even with the threat of an enemy naval bombardment, a man could dig revetments, tunnels and other installations just so fast and no faster in the coral earth of Biak Island. It does not reveal the real throb of excitement that hung over the beaches all day as the cats seemed to dig, scoop and shovel harder and faster to fashion the revetments on the beach from which the tanks were to fire seaward on any invading enemy units.  The journal account also does not tell of the taut nerves that made men work without let-up at the end of a pick or shovel or at a typewriter all day long, making the record in coral and on paper of an enemy fleet coming ever closer to shores so newly won. It only tells of the parade of US naval might going past the island to give chase. Men lined the beaches that evening and broke into spontaneous cheers and finally went off to the mundane task of fighting the caved-up enemy on Biak. There was a feeling of relief, carelessness, and perhaps a little of mightiness.

The westward advance was halted on 4 June while a search for an approach around the Parai Defile took place. For three days elements of the 162d Infantry tried to break through this enemy stronghold. On 5 June an attempt was made with the support being furnished by a destroyer, a rocket LCI and flak boats but despite this strong support the mission failed. The following day the 162d probed the defile to maintain pressure on the enemy but made no gains. Attempts to make an enveloping movement over the ridges   also failed. Meanwhile, the 186th pushed patrols to the south and west in an effort to discover routes leading over the coral ridges to the Mokmer drome. Except for these patrols there was no activity on 6 June.

On 5 June the 186th Infantry, with the 2d Battalion of the 162d Infantry attached, moved to the eastern bases of the ridges dominating Mokmer strip where they reconnoitered throughout the following day. A coordinated attack, which resulted in the capture of Mokmer strip and the establishment of a beachhead south of the strip, was launched on 7 June.

Artillery fire had been laid down on the strip before the jumpoff and by 0850 the leading battalion was on the beach. The troops encountered no opposition getting onto the drome, but after about one and a half hours the Japs opened up on them with artillery, mortars and machine guns from the high ridge along the beach and from the high ground in what was called the Sump Hole Area, on the left flank of the Yanks. These enemy weapons were well camouflaged in dense scrub growth and well protected, as later determined, by defilade or by emplacement in caves. This intense fire continued for about four hours after which it decreased when Allied artillerymen and mortarmen used the muzzle blasts to direct their own fire on the enemy. The artillery also began to fire on the two dromes that lay beyond Mokmer. It was to be many weeks before these were to be captured but the softening up process had already begun.

Word reached the 162d Infantry that the 186th had reached the Mokmer drome. After another unsuccessful attempt to break the enemy blockade at the Parai Defile, amphibian craft carried elements of the 3d Battalion to a landing point at Parai Jetty on 7 June, thus by-passing the defile which had held up the advance.  The landing was completed during the afternoon but, due to the limited number of personnel employed in this movement and the strong enemy resistance, it was impossible for the 3d Battalion to make any headway for an attack on the defile.

Some attempt was made during the afternoon to reinforce both the 3d Battalion of the 162d Infantry and the 186th Regiment. Two tanks and Cannon Company did get ashore at Parai, but accurate heavy fire at Mokmer prevented LCMs and LSTs from landing until after nightfall. Then tanks and supplies were landed and the wounded evacuated. Many of the craft were hit during this period. Throughout the day the 186th Infantry had 14 men killed and 68 wounded.

The 1st Battalion, 162d Infantry, by-passed the Parai Defile and followed the 3d Battalion ashore at Parai on 8 June. The 2d Battalion of the 162d Infantry, which was attached to the 186th Infantry, began to move eastward from Mokmer drome on 9 June and established contact with its parent unit, thereby opening a sorely needed supply route. Following contact between the 1st and 2d Battalions, the latter reverted to 162d control.

Meanwhile, in the 186th sector, organization of the beach continued and defensive fires were coordinated.  The regiment was harassed by enemy patrols and mortar fire and it was noted that following the mortar fire the enemy sent trained dogs to locate Allied positions.  Several dogs moved to within a hundred yards of the 3d Battalion position on the beach, south of Mokmer drome. Some of the dogs stopped and barked while others approached the outposts and, without making a sound, trotted off to the west. The enemy then advanced and built up a line behind the dogs.

That night the Japs launched a heavy attack accompanied by the usual blood-curdling battle cries. A few of the enemy infiltrated the Allied positions and bayoneted a few men. Hand grenades were used effectively by both sides. The following morning, while still under heavy fire, the Americans buried their dead on the Mokmer drome near the beach. Eight American paid the supreme penalty while 42 of the enemy had fought the last time for the glory of the Emperor.

The beachhead was firmly established by 9 June and early that morning amphibian Buffaloes brought in ammunition and supplies and evacuated the wounded. Patrolling was begun toward the high ground to the north of the drome by Company B, which was using hand grenades and flamethrowers to clean out numerous caves in the vicinity of Mokmer. The beachhead area still was being plastered with heavy artillery and mortar fire.

Companies B and C of the 186th and the 1st Battalion command group took up the destruction of the enemy positions encountered the previous day north of Mokmer drome by Company B. An artillery barrage preceded the attack and continued until 1035. The advance was to the west with two companies abreast, Company B on the ridge and Company C on the right on the tableland. By 1100 both companies were under heavy fire. An hour later Company C detected a large number of the enemy moving around its north flank and killed 22 of them. The balance of the group continued moving east on Company C’s rear. Rocket-launcher and tank 75mm fire played on the enemy positions for two hours with no effect. The probing units withdrew south and the artillery laid down fire. Elements of the 162d Infantry relieved the 186th troops and the latter moved to the Mokmer drome. The 3d Battalion, aided by armor, continued the destruction of caves along the shoreline and the 2d Battalion, 162d Infantry, moved east with no resistance. Nine more tanks were attached to the 186th. Enemy long-range machine-gun fire proved quite annoying to the engineers working on the drome and soon increased to such an extent that work was halted, not to be resumed for ten days. Enemy artillery still was operating from deep defensive territory but had more of a harassing effect than the deadly fire of previous days.

Elements of the 162d Infantry continued to by-pass the Parai Defile and joined the regiment at Parai. The 2d and 3d Battalions began to move west toward Mokmer drome while the 1st Battalion defended the Parai Jetty area and applied pressure to the defile from the west. The movement to Mokmer drome was slow and required a f u l l day. The coastal corridor still was subjected to Jap fire and the two battalions had to move along the coast under the shelter of cliffs. This necessitated moving in a column of files, and men waded through surf that was waist-deep at high tide. At several points along the route the column was exposed to enemy fire and suffered some casualties.

During this period of fighting the 163d Regiment was consolidating supply lines and making scattered contacts with the enemy. On 11 June the 2d Battalion and Cannon Company, which had remained at Wakde, arrived at Biak and moved to the vicinity of Ibdi where they relieved units of the 162d Infantry with the mission of guarding the coast supply route. The remainder of the regiment patrolled, flushing out isolated enemy groups.

A coordinated attack against the ridges north and northwest of Mokmer drome was launched by the 162d and 186th Regiments on 11 June. For this attack the two regiments were deployed abreast from the coast to the ridges north of Mokmer. The 3d Battalion,  162d Infantry, moving along the ridge just north of the drome, met stiff resistance from Jap pillboxes and could not maintain the advance with the other battalions. By 12 June the 2d Battalion, 162d, and the 186th Regiment reached their objective. The 3d Battalion,  162d, was unable to proceed west along the ridge until Company L made a flanking  movement to the north and dislodged the Japs from the crest of the ridge. One small pocket of resistance remained between Company L and its parent unit but this was eliminated during the following day. Meanwhile, shortly after noon on 12 June, word came that the Jap positions in the defile area between Parai Jetty and Ibdi had been reduced and the defile now was open to traffic.

The 2d Battalion, 162d, moved north and took up a position on the ridge on 13 June. The 2d and 3d Battalions, 162d Infantry, tried to reduce the resistance between them, and made short advances despite determined resistance. The 1st Battalion dispatched patrols north from its position on Mokmer drome in an effort to locate possible routes of advance for a proposed wide envelopment by that battalion. The 1st Battalion, 162d, moved north via a trail through the 3d Battalion, 162d. The 1st Battalion, 186th, moved north beyond the 1st Battalion, 162d, and these two units turned west and made a coordinated attack in a west and southwest direction.

This attack continued through 14 June but due to rough terrain and enemy resistance it did not progress as rapidly as had been planned. During the night the Japs attacked, using tanks, but these attacks were repelled. However, the 1st Battalion, 162d, suffered many casualties. On this date the 162d Regiment reached the main enemy defense known as West Caves while the 186th Infantry continued patrolling toward Borokoe drome and the area south to the coast line.

The situation on 15 June found the two regiments  deployed abreast with the 3d Battalion, 186th, on the left or coastal flank. North of this unit were the 2d Battalion, 186th; 2d Battalion, 162d; 3d Battalion, 162d; 1st Battalion, 162d and the 1st Battalion, 186th, which held the right or inland flank.

Prompted by an Air Corps report of probable attempts by the Japs to send reinforcements to Biak and by the marked signs of fatigue among the troops. General Fuller, commander of the Biak forces, requested another regiment as reinforcements. General Krueger placed little credence in the Jap’s ability to strengthen his Biak garrison, but nevertheless he sent the 34th Infantry of the 24th Division to Biak where it arrived on 18 June.

Because of the slow progress being made on Biak and the failure to secure the airdromes at an early date, as directed. General Fuller was relieved as commander of Hurricane Task Force. Continuous heavy fighting, coupled with extremely difficult terrain, intense heat and the scarcity of water had tired the task force troops to a critical degree and was largely responsible for the delay. The situation at Biak indicated that the success of future operations was threatened. General Eichelberger replaced General Fuller on 15 June and three days later General Fuller, at his own request, also was relieved from command of the 41st Division and was replaced by General Doe, who subsequently received his second star. In a final statement to the officers and men whom he had led overseas and through many months of bloody combat. General Fuller gave his thanks for their efforts and praised the Sunset Division as one of the finest group of men he had ever commanded. With General Fuller’s departure the Jungleers lost an excellent and highly admired soldier but in General Doe the men got a worthy successor.

In a sense, 17 June marked the halfway point in the Biak campaign. Although weeks of combat lay ahead, the primary objective, Mokmer drome, had been seized although it had not been fully secured. Secondly, the initial phase of the campaign was past. That phase where enemy air, naval and ground arms could still be coordinated in carrying out prearranged tactics definitely was over. True, there still were bombing attacks but these were mostly of a harassing nature and about the only naval action was to be the  dispatching of a submarine to Biak near the end of the campaign in a futile effort to evacuate some of the defeated elements of the enemy force. Last, and by no means the least significant, was the change in command and the introduction of more fresh troops into the fight.

At the time General Eichelberger took over, the ground situation was as follows: Shortly after the landing the 162d Infantry had approached Mokmer drome by a drive along the coast but had failed to secure the drome so that it could be used. This unit had extended its lines without obtaining control of the dominating ridges along the coast. As a result its flank was attacked at the Narrows, a point in the vicinity of Mokmer Village at which the high coastal ridge extended almost to the sea. While advance units of the 162d Infantry were withdrawn by water and by overland movement the situation was countered when the 186th Infantry moved north of Bosnek, then west where it stormed the airdrome from the north and northeast.

The 186th had moved east along the coast after landing and the move to the drome necessitated a long march over very difficult terrain. Heavy fighting was continuous, the water supply was critical and many men were close to the point of exhaustion.

After the 186th seized Mokmer drome it relaxed, but only momentarily. Although it had pushed through the high ground north of the drome, it failed to secure the drome after capturing it. The Japs again occupied the ridges and brought the drome and its captors under fire. This halted work on the drome and the 186th pivoted to face the Jap positions in a northeasterly direction. Several frontal attacks were unsuccessful.

After reorganization following its Narrows engagement, the 162d moved up to the trail leading northwest of Mokmer drome and reached the Sump Holes. This regiment attempted several frontal attacks but was denied success.

When the 163d landed at Bosnek on 27 May it took up the 186th’s mission of eliminating the enemy in the ridges east of Bosnek. This mission was enlarged to include the ridges west of Bosnek as far as Parai Town.  The 163d operations consisted of patrolling and mopping up areas bordering the coastal track, and securing the water point north of Bosnek which the 186th had captured prior to its move to Mokmer drome. The 3d Battalion, 163d Infantry, had moved overland to the northeast of the enemy’s main defenses, and succeeded in establishing a squad on the crest of Hill 320. This hill was the dominating terrain feature within the entire zone of action north of the dromes and afforded excellent observation. This move evidently took the Japs by surprise.

In the 186th sector patrolling toward Borokoe drome continued and the artillery registered on this objective.  The 2d Battalion, 186th, relieved the 2d Battalion, 162d, and attacked west in order to close the gap that had existed for several days between 2d Battalion, 162d, and the remainder of that regiment to the northeast.  The closing of the gap got under way on 16 June. During the action Private Edward Morales singlehandedly cleaned out a hasty emplacement containing several Japs and was proceeding toward another when he was killed by snipers. Private Morales made a one-man frontal attack on the enemy machine-gun emplacement with his Thompson submachine gun and grenades.

He killed eight of the enemy while under intense fire before he was cut down. For this action.  Private Morales was posthumously awarded the DSC.  About mid-morning contact was made with the 3d Battalion, 162d Regiment. During this attack the Jungleers had 15 men killed and 35 wounded and killed 62 of the enemy. While this gap was being closed, the 1st Battalion, 162d Infantry, was pinned down by fire from the battle raging on its left flank and could not move.

Patrolling toward the Borokoe and Sorido dromes took place during the next few days and plans were laid for a coordinated attack to be launched on 19 June.  This required reorganization within all units. The mission of this attack was to envelop the enemy right (south) flank, seize the high ground north of Mokmer drome and occupy the ridgeline one thousand yards east of Borokoe drome. This last move was to pave the way for the attack on Borokoe and Sorido dromes.

The 163d Infantry was directed to increase the tempo of its patrol activities and to locate and engage enemy forces within its area. From the number of caves, holes and precipices it was evident that the Japs were free to choose the location of their positions at w i l l . The enemy’s main strength could be shifted to counter any localized attack that the American forces might make.  To prevent any shift of enemy strength prior to the 19 June attack, the 3d Battalion, 163d Infantry, was to hold its position in the vicinity of the Sump Holes. In the coordinated attack the 162d was to continue its frontal assault while the 186th attacked north and east from its positions on the ridge above Mokmer drome.

This would envelop the enemy and put the 186th on the high ground to the north and west of the Jap positions while the 2d and 3d Battalions of the  162d Infantry would be on the low ground to the south in defensive positions. The 3d Battalion, 163d, would be on the high ground to the north and west of the enemy.

Prior to the attack on 19 June a preparation was laid down by 4.2-inch mortars and artillery. The 2d Battalion, 186th Infantry, was the assault unit. There was no resistance encountered until the lead companies, E and F, began advancing up the ridge and were greeted by mortar fire. By 1130 these two companies were on the objective while Company G covered the rear. The 3d Battalion followed the 2d and Companies K and L occupied the northern half of the objective while Company I protected their rear. The attack was a complete success and the enemy was overrun to the Regiment, engaged the enemy at the eastern end of the Sumps during the 186th Infantry attack while the remainder of the 162d Regiment stood fast. It was becoming more and more apparent that the Sumps were the key position in the Jap defense north of the dromes.

Destruction of the Sump Hole area and seizure of Sorido Village was next on the agenda. The attack got under way at 0630 on 20 June when the 34th Infantry of the 24th Division entered the fight. This unit took the Sorido and Borokoe dromes and occupied Sorido Village against moderate resistance. Meanwhile, the 162d Regiment continued operation in the Sump Hole area. The 1st Battalion moved to the surface of the caves and killed many Japs by dropping drums of gasoline into the caves and igniting it with high explosives. Late in the afternoon the attacking units withdrew after being unsuccessful in attempts to reduce the Sump caves.

The following day the 1st Battalion again sent troops to the Sumps preceded by two patrols on the high ground on each side of the Sump Hole area. Automatic and small-arms fire covered some men who went f o r w a r d and sprayed sniper positions with flame-throwers. Freed from sniper trouble and supported by two Sherman tanks, the infantrymen reached points on the western lip of the Sumps from which they could fire and throw grenades into the entrance of the cave.  As enemy soldiers ran out they were riddled with bullets.  However, the main cave entrances were shielded by stalagmites and stalactites and were firmly held.

Cave 1 at the western end of the Sumps was attacked on 21 June and tank fire and flamethrowers were brought to bear on its mouth. To add further to the enemy’s distress, five large drumfuls of gasoline were poured into the cave through the crevices and seepage points on top of the cave and then ignited. Explosions roared throughout the following day and it was believed that the fire had reached the ammunition stores. An attack against a second cave position failed and the Jungleers pulled back for the night and 4.2-inch mortars took up the fight.

That night the Japs made an effort to reach Korim Bay. The story was told by a Jap prisoner who said that Colonel Kuzume, commander of the Japanese 222d Infantry, held a ceremony in the main Sump Cave at 0300 on 22 June. He urged all able-bodied soldiers to attempt a withdrawal to the north using any possible means. Documents then were destroyed and the gasoline-soaked regimental colors were burned. The Japs tried a suicidal effort to break through the 186th lines. Twice heavy machine guns broke up the attack in the early stages but in the third attempt the enemy penetrated the inner defenses and engaged in hand-to-hand combat, using bayonets and grenades. During the night 115 Japs were killed while the 186th had one man killed, this occurring when a Jap jumped into a soldier’s foxhole and fired a grenade which killed both men. Later that morning the lip of the Sump was secured.

Several experiments had been tried in the reduction of the Sump caves, but none was so effective as the 850-pound charge of dynamite lowered into the cave by a winch and fired electrically by the engineers. Few Japs survived this explosion, and of those who did many were driven insane.

A systematic reduction of the caves was carried out using tank fire, explosives and flamethrowers. By 27 June the last Jap had been killed within the Sump network and the Allied troops entered the inner recesses of the caves where they found considerable quantities of equipment. Living conditions in those last few days must have been unbearable as the smell of rotting bodies permeated the tunnels and inner chambers. By the end of 23 June nearly all organized enemy resistance had ceased but scattered opposition was encountered. 

With the West Caves completely wiped out, attention was turned to the enemy pockets in the ridges north of Mokmer and Ibdi Towns. The 163d Infantry, less its 3d Battalion, had been patrolling the ridges between Parai and Warwe. The enemy situation had developed as follows:  On 21 June, Company F, 163d Regiment, began an attack to the southwest from its location on the high ground northwest of Ibdi. About one and a half miles northwest of Ibdi it ran into strong resistance. The unit had missed the enemy outposts and when it opened fire it received fire from three directions. Other elements of the 163d Infantry were due north of this position on a piece of high ground and observed the fire. Heavy machine-gun fire from this position evidently led the Japs to believe that they were being attacked by a force of considerable size and they opened up all along their positions on the high ground to the north. During this barrage. Company F withdrew to a point along the ridge which it could hold. One platoon remained in that location to prevent any move to the east and the remainder of the company moved back to Ibdi Town.

Throughout 22 and 23 June the Jap positions along the ridge were subjected to harassing artillery fire and on 24 June the enemy position was bombed by twelve B-25S. From the air it was observed that the main enemy defensive position was apparently in a large cylindrical hole with caves leading off from its side. On this date the 163d participated in a coordinated attack with the remainder of the 41st Division to seize the ridge extending from a point northwest of Ibdi to a point north of Mokmer Village. The 3d Battalion, 163d Infantry, had been under control of the 41st Division but was released to the regiment and placed in reserve, occupying a position on the trail north of Mandon.

In order to facilitate the accomplishment of the regimental mission, it was decided to eliminate the enemy strongpoint northwest of Ibdi which had been under artillery and aerial bombardment. The maneuver was to be an enveloping movement. The 1st Battalion, attacking from north and northwest, and Company F, attacking from the southwest, were to be the assault elements, while Company G occupied a position to the east where it could block and hold.

After a heavy preparatory fire the attack was launched at 0530 on 26 June. It is significant to note that this attack was launched before daylight, a move too infrequently attempted by American forces in jungle fighting. The result was highly satisfactory and completely surprised the enemy. Many enemy forward positions which normally were occupied during daylight hours were found unmanned, this factor being an aid to the Jungleers during the initial stages of the attack. Later a series of enemy emplacements, well organized in depth and protected by heavy sniper fire, were found. The close of the day’s fighting found the regiment in position as indicated on map 21.

By the end of 27 June, Company F had moved to a position adjoining the Company G area and was assisting the latter in blocking and holding. Slight advances were made by the attacking forces during the day and they were prepared to carry on the attack the following day. In the meantime, it was known that the Mokmer Pocket (or East Cave) still was occupied by the enemy.  This position was located in the cliffs north of Mokmer Town, and though seldom active, it remained a potential threat to traffic on the road to the airdromes.  On one occasion the road had to be closed when the Japs placed mortar fire on the shoulders of the road. 

A company of infantrymen from the 163d Regiment was given the mission of reducing this position but by 27 June had met with little success. Several fire fights took place but their results were unobserved. On 27 June the Japs shelled the highway and again halted traffic on the main road. Twelve P-40s took to the air and for one hour bombed and strafed the position. At the completion of this strike silence reigned over the enemy’s stronghold and later the cliff positions were entered. By 4 July they were cleared.

It was on 27 June that General Eichelberger’s I Corps Headquarters was ordered back to Hollandia and command of Hurricane Force was handed over to General Doe. By this time the situation on Biak had become stabilized and the complete enemy dispositions were known. All organized pockets of resistance were under constant attack and mopping up activities were being conducted in the West Caves and the area west of Mokmer drome.

The 162d Infantry was ordered to relieve the 34th Infantry in place on 28 June and by 1 July had completed this move. The mission was a defensive one: to secure the western sector of the Division defense area to prevent enemy interference with the development and operations of the drome and dump areas. Patrol activities were carried out by this regiment through 9 July.

The tedious job of cleaning up scattered units of Japs was so successful that by 9 July the only organized enemy resistance was the pocket 1,200 yards north of Ibdi. For two days this pocket came under aerial attacks, and then one company of the 163d Infantry entered it from the east. This unit was halted by heavy fire and resistance remained firm until 22 July when a terrific bombardment was laid down by B-24s, mortars and artillery. Two companies from the 3d Battalion, 163d Infantry, launched a coordinated attack and by nightfall had broken all organized resistance. Until this final attack took place one company of the 3d Battalion remained in constant contact with the enemy, slowly reducing pillboxes with the aid of bazookas, artillery and mortars. During this fight 132 Japs were killed while only two surrendered. Mopping up continued in the Ibdi pocket until 26 July.  Patrol activity was conducted in all sectors and on 15 July the 34th Infantry left Biak to rejoin its parent unit, the 24th Division, at Hollandia.

The 2d Battalion, 163d Infantry, moved by LCMs to Korim Bay on 3 August and patrols began to operate south, east and west from Korim Village. The 2d Battalion, 162d Infantry, later joined in these mopping up activities.

The 1st Battalion, 186th Infantry, aided by naval gun fire and air support, landed at Wardo on the southwestern coast of Biak. The landing was unopposed and patrolling continued until the campaign was officially terminated on 20 August.