Sitkoh Bay spent the month after commissioning completing her fitting out and making short shakedown and trial cruises along the northwestern coast of the United States. On 28 April, the escort carrier entered port at Alameda, California, loaded cargo and embarked passengers. She stood out of Alameda on 30 April, bound for Pearl Harbor, and began the first of many routine voyages shuttling planes, pilots, and air crewmen back and forth between the front line and rear areas. The majority of her missions carried her from Pearl Harbor, or via Pearl Harbor from the California coast, to various islands in the southern or central Pacific which served as staging areas for the war being waged farther north or west. In the latter part of 1944, her ports of call were Majuro in the Marshall Islands, and Manus in the Admiralty Islands. From these two points, planes were staged on to the 3rd and 7th Fleets, respectively. In January 1945, the South Pacific was dropped from Sitkoh Bays itinerary, and she concentrated on replenishing the 3rd Fleet in the Central Pacific. Her ports of call included Apra Harbor, Guam, in the Marianas; Roi Harbor, Roi Island, and Eniwetok in the Marshalls; and Ulithi Atoll in the Western Carolines. Her missions in early 1945 were in support of the campaigns in the Philippines, the assault on Iwo Jima, and the preparations for the invasion of Okinawa. Sitkoh Bays only action came on 7 April 1945 while she was delivering Marine Air Group 31 to Okinawa. At 1528, a Yokosuka P1Y "Frances" dove at the carrier. Sitkoh Bays anti-aircraft gunners combined with an F4U Corsair on combat air patrol from to shoot down the interloper about 100 yards off Sitkoh Bays port beam. The next day, she cleared the area for Guam en route to Pearl Harbor and a return to her replenishment routine. After the cessation of hostilities with Japan on 15 August, Sitkoh Bay joined Task Group 30.8, the replenishment group for the 3rd Fleet, and cruised with it off the southeastern coast of Honshū from 25 August-5 September. On 10 September, she entered Eniwetok and departed the next day for Guam. For the next month, she made voyages between Guam, Samar Island in the Philippines, and Okinawa, returning to Pearl Harbor on 18 October and San Diego on the 26th for an availability period. After further voyages to the Central Pacific, Sitkoh Bay returned to the United States and was placed out of commission, in reserve, on 30 November 1946 at Bremerton, Wash. On 29 July 1950, Sitkoh Bay was recommissioned with Captain C. W. Lord in command. She was assigned to the Military Sealift Service, and for the next four years, she sailed between the west coast and Japan, supporting U.N. forces in Korea. Her major ports of call were San Francisco, San Diego, and Pearl Harbor and Yokohama and Yokosuka in Japan. Sitkoh Bay departed from this west coast-to-Japan routine three times over those four years. In March 1951, she delivered a load of F8F Bearcats to the French forces at Saigon in French Indochina and then visited Manila, P.I., before returning to California-to-Japan runs. In September, she visited Pusan, Korea. Sitkoh Bay ventured from her normal sea-lanes again in May 1952, when she sailed back to San Francisco from Yokosuka. The escort carrier ceased operations again in 1954 and was placed out of commission, in reserve, on 27 July. She joined the Pacific Reserve Fleet and was berthed at San Francisco. On 12 June 1955, the mothballed escort carrier was redesignated a utility aircraft carrier, CVU-86. In mid-March 1958, she changed berthing areas, moving from San Francisco to San Diego. On 1 April 1960, Sitkoh Bay, by then reclassified as a cargo ship and aircraft ferry, AKV-86, was struck from the Naval Vessel Register. Her hulk was sold on 30 August 1960 to Eisenberg & Co. of New York City for scrapping.
