[5] Following the loss of Hollandia, to the east, in April 1944, the 26 miles (42 km) of coastline and surrounding area of Toem-Wakde-Sarmi was an isolated coastal salient for the Japanese.

[citation needed] Lone Tree Hill rose from a flat, coastal plain about 6,000 feet (1,800 m) west of the main jetty in Maffin Bay.

The hill was named for a single tree depicted on its crest by U.S. maps; it was a coral formation, covered with dense tropical rain forest and undergrowth.

The eastern slope was fronted by a short, twisting stream which the Americans named Snaky River.

With Lone Tree Hill in American possession, Maffin Bay became a major staging base for six subsequent battles: Biak, Noemfoor, Sansapor, Leyte and Luzon.