She moved to Lingayen in northern Luzon to load soldiers of the 6th Army's 33rd Division for transportation to the Japanese home islands and occupation duty.

From January to March 1946, she conducted amphibious and fleet training in the eastern Pacific before returning to the Far East to resume her support missions for the occupation forces.

During the fall of 1949, she returned to the West Coast to participate in Operation "Miki", a large-scale, joint-service exercise staged out of Puget Sound, Washington, which simulated the invasion and defense of the Hawaiian Islands.

She participated in Operation "Port-rex", an Atlantic Fleet Amphibious Forces assault exercise held at a small island near Puerto Rico.

After a liberty call at San Juan, Puerto Rico, at the operation's conclusion, she retransited the Panama Canal and resumed duty with the Pacific Fleet.

After a resumption of Japan-to-Korea runs, which she conducted from July to November, she headed back to the United States, arriving on the West Coast on 16 December 1951.

The last-named group of islands came into her sphere of operations because of their proximity to mainland China and the consequent communist threat to their Nationalist Chinese populations and garrisons.

By the following fall, she found herself halfway around the world in the West Indies supporting the Navy's quarantine of Cuba called by President Kennedy to rid that island of offensive Russian missiles.

Otherwise, the decade between 1955 and 1965 proved relatively normal, made up of the usual resupply voyages, amphibious and fleet exercises, port visits, and ever-recurring overhauls.

Near the end of 1964, however, the attack cargo ship entered a geographic region that dominated her western Pacific deployments for the remainder of her career — South Vietnam.

During her 1968 deployment, Washburn spent four extended tours of duty off Vietnam again carrying troops and supplies to and from operational areas throughout the southern half of the country.

From May to October, the ship cruised the coast of Vietnam, departing periodically to transport Marines to Okinawa, to make liberty calls at various ports in the Far East, and to replenish in Japan and in the Philippines.