In September 1942, MacArthur decided to outflank Japanese troops on the Kokoda Trail by sending an American regimental combat team over the Owen Stanley Range. Two alternate means of crossing the mountains seemed possible. One, the Kapa Kapa Trail was known to climb to elevations above and present formidable obstacles. Casey and Sverdrup took charge of investigating the Abau Trail. They reached Abau on 18 September. Casey explored the harbor, taking depth soundings from a native canoe. Sverdrup set out for Jaure with a party of one American, two Australians from the Australian New Guinea Administrative Unit, ten native police from the Royal Papuan Constabulary and 26 native carriers. After eight days on the trail, scaling heights of , Sverdrup concluded that it would not be practical for troops to traverse the route and turned back. Meanwhile, Casey had concluded that the harbor was too shallow even for lighters. However, the trip was not a total loss, for Sverdrup had sighted a plateau north of the Owen Stanley Range suitable for airstrips, allowing troops to be flown across the Owen Stanley Range. Casey was awarded the Silver Star.