The battle of Lone Tree Hill or Wakde-Sarmi (17 May-2 September 1944) was a hard-fought contest for control of a strip of the New Guinea coast near the island of Wakde, and saw the Americans eventually win control of a large enough area for them to use as a staging post on the way to further advances.
The battle was fought along a roughly eight mile long stretch of coast that ran west from Wakde Island to Maffin Bay and on to Sarmi. Tiny Wakde Island is a couple of miles off the coast opposite the village of Toem. From Toem a coastal track ran west to Arare, then to Maffin Bay, above five miles to the west of Toem. From Maffin bay the coast runs north-west for file miles, past Sawar, to Sarmi, on a small headland. The Japanese had built airfields at Sawar, and on Wakde Island, and were working on another near Maffin Bay. The coastal strip was generally quite flat, although also fairly narrow, with higher ground nearby. A number of creeks and rivers flow into the sea along this coast. First was the Tor River, between Arare and Maffin Bay. Next was the Tirfoam River, which flows into Maffin Bay. The Woske River flows into the sea to the west of Maffin Airfield. Finally the Orai River runs into the sea between Sawar Airfield and the village of Sarmi.
One key feature was Lone Tree Hill, a steep sided hill just to the east of the new airfield at Maffin. The hill got its name because US maps showed it with a single tree on the summit. A number of rivers flowed into the sea along this stretch of coast, with the most important being the Tor River, just to the east of Maffin Bay.
At this point the Wakde-Sarmi area had been made a key position on the new Japanese main line of resistance, pushed ever further west by Allied victories on New Guinea. By the time of the attack the Japanese had decided to pull the defensive line back to Biak, although that decision was only made on 2 May. Only a few days later, on 9 May, the line was moved west again, to Sorong and Halmahera, leaving Biak outside the perimeter. Biak was to be defended as an outlying bulwark of the main line, but the Wakde area was written off.
The attack was carried out in order to give the Allies a base on the coast between Hollandia, attacked on 22 April, and Biak Island, their next major target off the coast of New Guinea. The American planners also believed that the Japanese bases in the area posed a threat to their base being developed at Hollandia.
The landings were carried out by the Tornado Task Force, which initially contained the 163rd Regimental Combat Team from the 41st Division. This force was commanded by General Jens A. Doe, and had recently captured Aitape in three days of fighting. The rest of the division was allocated to the invasion of Biak Island, further west along the coast, which began later in the same month.
This move west brought the Allies out of General Adachi's Eighteenth Army area and into the area covered by the Japanese Second Army, which had the fresh 32nd, 35th and 36th Divisions. The 163rd was thus up against a much stronger opponent than at Aitape. The Japanese had around 10,000 men from Lieutenant General Hachiro Tagami's 36th Division in the Maffin Bay area, and had created a string of strong defensive positions along the coast and some way inland. Tagami also had anti-aircraft guns and support troops under his command. The forces around Sarmi were called the Yuki Group. Just before the American attack this force was split into three. The Right Sector Force defended the area facing Wakde Island, and contained 1,200 men and the garrison of the island. The Centre Sector Force covered the area from the Woske River to the Sawar Creek, including Sawar airfield and contained around 2,500 men. Finally the Left Sector Force covered the area west from the Sawar Creek to the Tevar Creek, just west of Sarmi. It had another 2,500 men. In total Tagami had 11,000 men under his command, with about half of them combat troops and some on detached duty to the east.
The 163rd landed at Arare village, south-west of Wakde Island, on 17 May. This landing beach was chosen in order to bring the assault force out of range of the Japanese on the island. The landing went well, and the three battalions of the 163rd were on shore by 7.35am. The 2nd Battalion then began to advance east and soon captured Toem, on the shore opposite Wakde Island. At the same time the 3rd Battalion probed west, and reached the Tor River. Once the mainland beachhead was secured, the next target was Insoemanai, the smaller of the Wakde Islands. This undefended island was captured in preparation for the upcoming attack on the larger Wakde Island. The only significant opposition on 17 May came from the garrison of Wakde Island, which eventually opened fire with mortars and machine guns. The only major Japanese activity on the mainland came when General Tagami sent orders to his detached forces to return to the Sarmi area.
Wakde Island itself was attacked on the following day, 18 May, and fell after a few days of fighting, but the battle on the mainland would prove to be much harder.
On 19 May the Japanese on the mainland were ordered to counterattack. General Tagami planned a two-pronged attack, with the returning detached forces attacking from the east and the Central Sector Force attacking from the west. While these forces prepared for the attack the Right Sector Force formed up on the Tor River and prepared to resist any Allied advance towards the Maffin and Sawar airfields.
The first American patrols crossed the Tor late on 18 May. On the following day they found the first signs of more determined resistance. On 20 May the Japanese attempted to push the Americans back to the Tor so they could establish their defensive line, but the attempts failed. On 21 May the troops near the mouth of the Tor came under artillery fire, but no infantry attack followed. On the same day the 158th Regimental Combat Team arrived to reinforce the Americans.
The First Attack on Lone Tree Hill
On 22 May General Krueger decided to expand the role of the Tornado Task Force at Wakde. Instead of just capturing the island and the nearby coast the force was now ordered to attack west towards Sarmi to disrupt any Japanese plans for a counterattack. The task was allocated to the 158th Infantry. At about the same time General Doe was recalled to join his own 41st Division for the upcoming attack on Biak. He was replaced by General Edwin D. Patrick.
The first step was an advance from the Tor to the Tirfoam on Maffin Bay. This began on 23 May, and the Japanese put up more resistance than expected. Troops allocated to 24 May had to be committed on 23 May, but the Americans still failed to reach their targets for the day. More progress was made on 24 May, supported by tanks. Three of the four tanks committed were damaged during the day, but none were destroyed and they helped the infantry push some way forward.
The Lone Tree Hill position was the only point where the high ground came all the way to the beach. A series of spurs ran north from the main hills towards the coast, with a steep sided ridge (Hill 225) running due north from the top of Mt Saksin and a more gentle ridge running parallel to it to the east. A steep sided valley separated these two ridges from Lone Tree Hill which filled the gap between the ridges and the coast. The coastal road moved inland here and ran through this valley then turned north to run along the western foot of the hill to reach the coast near Maffin Airfield. The hill itself was a coral hill covered with dense rain forest and undergrowth, 175ft high, and covering an area 1,200 yard by 1,100 yards. It made a formidable defensive position. General Tagami realised this, and from 23 May he was based just to the south-west of Mt. Saksin. By the time the Americans reached the foot of the hill it was defended by the Right Sector Force and by the Yuki Group, a new force made up from the Centre and Left Sector Forces.
On 25 May the 2/158th advanced up the coast. By the end of the day the 1/158th had taken the lead and was most of the way to the Snaky River, the name the Americans gave to a short stream just to the east of Lone Tree Hill.
The Americans still didn't realise how strongly held Lone Tree Hill actually was. Their plan for 26 May was to capture the hill and a native village at the eastern end of the pass, and if possible push on to the Woske River, 2,000 yards to the west of the hill. The attack was supported by naval fire from two destroyers, then by a fifteen minute artillery bombardment. The bombardment ended at 8.45 and the infantry attack began a few moments later, but the starting point was too far to the east. By the time the Americans were ready to attack, the Japanese had been able to get back into their defences. The Americans were only able to advance 1,000 yards during the day, and the Japanese still held all of the high ground. About the only significant American achievement of the day was to discover how strongly defended the hills actually were, but that still doesn't appear to have sunk in at headquarters. The orders for 27 May were for the 1/158th to capture the valley and Lone Tree Hill, the 2/158th to take Hill 225 and for the two units to then push on to the west.
The attack on 27 May began with fire from two destroyers, which lasted from 7am to 7.45am. It was then followed by a well planned artillery bombardment, before at 8.30am the infantry began to move. On the left Company F of the 158th thought it had pushed onto Hill 225, but later discovered it was on the gentler ridge to the east. They were able to reach the top of this ridge, where they were joined later in the day by Company E. Company B, in the defile itself, was held up. To the north Company A actually managed to reach the top of Lone Tree Hill, and dug in for the night at the top of the eastern slopes.
For the attack on 28 May two tanks were moved by sea to the mouth of the Snaky River. They were to advance south to support the fighting in the defile. Two companies from the 158th were take part in this attack, while two more (A and C) advanced west off Lone Tree Hill. On the hill Company A attempted to advance north to clear the seawards side, but was stopped by the Japanese defenders, who were dug into caves on the cliffs. Company C advanced more to the north-west, but was hit on its left flank. The two companies found themselves in an exposed position on the western slopes of the hill, with ammo running short and a sizable Japanese force apparently about to attack. They were thus ordered to withdraw to the Snaky River. In the defile companies B and E were held up all day, and made no progress. This ended the 158th's first attempt to capture the Lone Tree Hill position.
General Patrick decided that he didn’t have enough men to extend his perimeter any further west against such fierce resistance, and instead decided to focus on dealing with the Japanese troops still left to the south and east of the main part of the beachhead. His decision was confirmed when a force of 200 Japanese troops attacked Toem on the night of 27-28 May. He was also about to lose two battalions from the 163rd Infantry, needed on Biak, and so had to pull one battalion from the 158th back east across the Tor River to defend the main beachhead. The rest of the regiment had originally intended to hold the line of the Snaky River, but this wasn't a good defensive position, and instead the Americans withdrew 2,000 yards to the Tirfoam River. General Patrick originally opposed this move, then approved it, and then changed his mine yet again and removed Colonel Herndon from command of the 158th. The Colonel was soon vindicated when it became clear that the Japanese were planning a major offensive of their own. The new defensive line came under attack on the night of 29-30 May, an attack that might well have succeeded against the shakier line on the Snaky River, but that was repulsed on the Tirfoam.
The Japanese Counterattack
By the night of 30-31 May the Tornado Task Force was weaker than it had been for some time. The 1st and 3rd Battalions, 163rd Infantry, had left for Biak. The remaining battalion held the eastern flank of the beachhead. The 2nd and 3rd Battalions, 158th were in the west, on the far side of the Tor, with artillery on the eastern side of the river and the 1st Battalion, 158th, in the centre around Arare. That night the Americans were spread out in twenty one separate defended areas, the weakest containing widely scattered anti-aircraft batteries.
Ever since the attack the Japanese had been withdrawing from the area east of the Allied bridgehead, with the troops gathered together as Matsuyama Force, while another attack force, the Yoshino Force, had been moving east from the main Japanese position, moving well inland of the American positions. By 28 May the Japanese had 2,000 men in place south of Toem, from a total of 8,000 men in the area.
On the night of 30-31 May the Japanese attacked north towards the scattered American positions on the coast west of Toem. The first attack hit No.6 gun position of Battery B, 202nd Antiaircraft Artillery Battalion at 6.30m, and forced the Americans to retreat east to join No.7 Gun, Battery A. This position was subjected to repeated attacks from 6.40pm to 4.30am on 31 May but managed to hold them all off.
The second attack hit No.6 Gun, Battery A, to the west of No.6, Battery B, just after 6.30pm. This attack started with harassing fire, and later in the night the Japanese attacked at least twice without success.
Further west No.8 Gun, Battery B, was also attacked at about the same time. Here the key anti-aircraft gun soon overheated, and the men were forced to scattered into the brush, where they avoided further attack until the attack ended at 4.30am.
The Japanese captured one .50 machine gun, damaged a multiple .50in gun, damaged two 40mm guns and then moved to attack the 1st Battalion 158th Infantry. Company B was hit first, soon after the attack on the guns. At 7pm the 1st Battalion came under rifle and machine gun fire, and at 10pm the Japanese began a prolonged assault on Company B. This was repulsed with very heavy losses - the Japanese lost at least 52 dead, the Americans 12 dead and 10 wounded.
On the morning of 31 May General Patrick, in the belief that he was about to lose the last unit from the 163rd, ordered the 158th to withdraw east of the Tor, keeping only a small bridgehead over the river. He planned to remain on the defensive until reinforcements from the 6th Division arrived. By the end of the day the original twenty two defended areas had been consolidated to eight, but the Japanese didn't return that night. Instead they remained in places south of the Toem position, before on 10 June beginning to retreat west to the main Maffin Bay position.
The Sixth Division Arrives
On 5 June the first troops from the 6th Division reached Toem, starting with the 1st Infantry Regiment and the 6th Engineer Battalion. The 158th Infantry was relieved from its defensive roles, but was then allocated to a renewed western offensive. Once again the first targets were Lone Tree Hill and Hill 225.
The attack began at 8.30am on 8 June. First the Americans had to push west from the Tor back towards the Lone Tree Hill area. The Tirfoam was reached on 9 June but the offensive then had to be suspended after General Krueger announced that he intended to use the 158th Infantry for the upcoming invasion of Noemfoor. This produced a period of patrolling, before on 14 June the 20th Infantry from the 6th Division replaced the 158th Infantry on the Tirfoam front. Just before this General Sibert, commander of the 6th Division, replaced General Patrick as commander of the Tornado Task Force.
General Sibert wanted to spent June consolidating the Toem position before beginning a push west on 1 July. He wanted to combine a thrust onshore with short-distance amphibious shore-to-shore assaults to bypass any strong Japanese defensive positions. General Kreuger vetoed this plan as he wanted the offensive to resume in June.
By the time the new attack began Lone Tree Hill was defended by 850 troops, with more nearby on Hill 225 and Mt. Saksin (around 1,800 at the start of the attack). Very strong defences had been built into the hill, taking advantage of a network of caves, especially towards the northern coastal end.
The 20th Infantry attack began at 8am on 20 June. By noon the Americans had advanced from the Tirfoam to the Snaky River and began to advance into the valley south of the hill. As before they ran into strong Japanese resistance, and ended the day east of the hill.
The morning of 21 June was spent patrolling in an attempt to locate the Japanese defensive positions. In the afternoon the 3rd Battalion launched an attack towards the north-eastern corner of the hill and immediately ran into an undiscovered cliff. This forced them to move north, where they found a heavily defended ravine. By the end of the day the Americans were back at their starting point.
The attack was renewed on 22 June, preceded by an air attack and then an artillery bombardment. This time the infantry were able to make more progress and were on top of the hill by 12.40. By 15.00 the Americans had four and a half companies on top of the hill, and held an area at the northern end of the summit, while another force held a position a little further south. For a moment it appeared that the Americans had taken possession of the hill, but then at 5.30pm two companies of Japanese infantry emerged from hiding and launched a counterattack on the American positions. The Japanese suffered heavy losses in the attack, but did manage to establish themselves to the east of the American outposts for a period before eventually withdrawing at midnight.
The Japanese returned to the attack early on 23 June, having received reinforcements from troops posted east of the Tirfoam River. The first attack came from a hidden ravine, and for an hour the 2nd Battalion came under heavy pressure before the attack was repulsed. The battalion was then ordered to join up with the 3rd, also on the summit, and form a single two-battalion perimeter. This move caused some problems. The Japanese held the 400 yard gap between the two battalions in some strength. The 2nd decided to outflank them by moving east off the hill, north along the Snaky River, then back west up the hill. This move brought them to the foot of the same cliff that had caused the failure of the attack on 21 June, so the battalion had to try again. They weren't back on top of the hill until 16.30, and this time they held a perimeter just to the north-west of the 3rd Battalion, but still not connected to it.
On the evening of 23 June the Japanese attacked both US battalions, this time hitting them from the east. The main attack was repulsed before the Japanese could close to bayonet range, but they continued to carry out small scale attacks all night.
24 June began with the first shore-to-shore attack of the campaign. Company K of the 1st Infantry was moved on ten LVTs to a beach on the western side of Rocky Point, the northern end of the hill, with orders to cut off the western approaches. The move was supported by thirteen LVT(A)s, carrying 37mm guns. The Japanese opened fire on the convoy, but were unable to stop the Americans from landing at 9am. The landing force was almost immediately pinned down, and reinforcements were needed. Company I joined them at 12.00 and four tanks were landed from LCTs at 13.30. The entire landing party was pinned down on the beach for the day, unable to make any progress inland. However on the hilltop the 2nd and 3rd Battalions of the 20th Infantry were able to make good progress, clearing the Japanese from their defensive positions around Rocky Point. They were then able to open a proper supply line back to the main American lines east of the hill, easing their supply problems. By the end of the day the Americans were effectively in control of the hilltop.
On 25 June the Americans continued to mop up the remaining Japanese positions on the hilltop. The troops on the beachhead to the west were still pinned down during the morning, but they were able to expand their beachhead during the afternoon, and even made tentative contact with the troops on the hilltop. Although they had made little physical progress, the amphibious troops had defeated the main part of the Japanese garrison of the hill. On the same day the Japanese decided to withdraw from the Lone Tree Hill area and form up a new defensive position west of the Woske River. A small force was to remain east of the river, but even they were to pull back to the south-west.
Mopping Up Operations
The capture of Lone Tree Hill secured the original Allied landing area facing Wakde Island, and removed any Japanese threat to Maffin Bay. The Japanese still had a well organised force west of the American positions, and the task of clearing this force up was given to the 3rd Battalion, 63rd Infantry and the 3rd Battalion, 1st Infantry, which replaced the 2nd and 3rd Battalions, 20th Infantry,. They were ordered to complete mopping up operations in the Lone Tree Area and advance west to the Woske River.
Mopping up operations on Lone Tree Hill took from 27 June to 30 June when the last Japanese positions were eliminated. On the same day the valley to the south was finally cleared.
On 1 July the 1st Infantry advanced to the Woske. On 4 July the 63rd occupied Hill 225 and on 5 July they reached the top of Mt. Saksin. Both areas were found to be deserted. The Japanese attempted to defend Hill 265, to the south-west of Hill 225, but were pushed off by the end of 9 July. The 6th Divisions' last major operation was to send a patrol west across the Woske. They advanced quickly across Sawar Airfield and didn't run into the Japanese until they reached Metimedan Creek, 1,500 yards past Sawar Creek. Soon after this the 6th Division was relieved by the 31st Division in order to free it up for operations on the Vogelkop Peninsula.
The 31st began to land on 18 July, and its commander, General John C. Persons, took command at Wakde-Sarmi. This was the first combat experience for the two regiments from the 31st that were deployed at Wakde, the 155th and 167th. The 31st's time at Wakde was largely dedicated to patrols and operating the staging post at Maffin Bay. It was then withdrawn to prepare for the invasion of Morotai Island, and at the end of August it was replaced by the 123td Regimental Combat Team of the 33rd Infantry Division. On 1 September General Krueger declared the Wakde-Sarmi operation to be over. This was an unusual end to a battle in that the Japanese retained an organised presence just to the west of the American beachhead, and the area was thus never entirely secured. On 1 September there were probably around 2,000 Japanese effectives in the area.
Maffin Bay became an important staging post during the campaigns further west in the South Pacific and in the Philippines. Five different task forces used it during 1944, using it to transfer troops and equipment from normal transport ships to assault ships. These troops then went on to take part in the invasions of Biak and Noemfoor, the Vogelkop Peninsula and the first stages of the invasion of the Philippines.
As the fighting moved away from the area the Maffin Bay and Wakde areas became less and less important. In late September even the airfield on Wakde Island began to be closed down, and in December it became an emergency strip only. The staging post in Maffin Bay was no longer needed, and in early 1945 all of the supplies were removed from the area. On 6 February the last American troops moved from the mainland to Wakde Island, which was held by one company from the 93rd Division from then until October 1945, when it was finally withdrawn.
The Americans lost 400 dead, 1,500 wounded and 15 missing between 17 May and 1 September. In the same period they estimated that they had killed 3,870 Japanese, and had captured 51. Many more Japanese troops had died of illness or been trapped in the defensive caves. By 1 September there were still around 2,000 Japanese troops in the area, but they no longer posed a threat to Allied operations.