Following an abbreviated fitting out and shakedown period in the Chesapeake Bay area, ammunition ship "Mount Hood" reported for duty to ComServFor, Atlantic Fleet, on 5 August 1944. Assigned to carry cargo to the Pacific, she put into Norfolk, where her holds were loaded. On 21 August, as a unit of Task Group 29.6, she transited the Panama Canal on the 27th, and continued on, independently, via Finschafen, New Guinea. "Mount Hood" arrived at Seeadler Harbor, in Manus Island of the Admiralty Islands, on 22 September. Assigned to ComSoWesPac, she commenced dispensing ammunition and explosives to ships preparing for the Philippine offensive.