Following the loss of Hollandia, to the east, in April 1944, the Toem-Wakde-Sarmi area was an isolated coastal salient for the Japanese. Nevertheless, elements of the Japanese 223rd and 224th Infantry Regiments, commanded by Lieutenant General Hachiro Tagami, were concentrated at Lone Tree Hill, overlooking Maffin Bay, and were blocking any further advance by the 158th Regimental Combat Team of the U. S. Army. The Japanese were in well-prepared positions, which included fortified caves. Meanwhile, the main body of the Japanese 223rd Infantry Regiment had outflanked the US units, and a battalion of the Japanese 224th Infantry Regiment, was retreating from Hollandia, towards the Toem-Wakde-Sarmi area.