LST-1077 was laid down 21 March 1945 by Bethlehem Steel Co., Hingham, Mass., launched without ceremony 18 April 1945, and commissioned 8 May 1945, Lt. I. W. Matthews in command.

After shakedown, LST-1077 was assigned to the Pacific Fleet and proceeded via the Panama Canal to Pearl Harbor arriving 19 July. She conducted training and provided services in Hawaiian waters until 29 August, when she sailed for Japan with occupation troops embarked.

She arrived Sasebo 22 September and departed on the 25th for Lingayen, P.I. to return personnel and equipment to Pearl. On 2 January 1946, LST-1077 was ordered to the west coast for inactivation. She arrived San Francisco 11 January, steamed to Astoria, Oregon on 3 May, and decommissioned there 31 July 1946. LST-1077 was placed in reserve and berthed with the Columbia River Group of the Pacific Reserve Fleet.

On 6 September 1950, LST-1077 recommissioned and joined the Pacific Fleet in the Far East where she served in operations in support of United Nations operations to repel communist aggression in Korea. She then returned to San Francisco in 1955 and decommissioned 12 May. She was again placed in reserve, and berthed with the San Francisco Group of the Pacific Reserve Fleet. On 1 July 1955, LST-1077 was named USS Park County (LST-1077) and subsequently moved to Bremerton, Wash., remaining in the Reserve Fleet there, until recalled in 1965 for Vietnam service.

In November 1965 Park County was towed from Bremerton to Portland, Oregon, for a complete modernization overhaul. On 9 April 1966 she again commissioned and, following shakedown, was assigned to Landing Ship Squadron 3, homeported in Guam.

Park County arrived in Vietnam in late August after carrying marines to Iwakuni, Japan. Her operations in support of the U.S. Military Assistance Command, Vietnam, included participation in Operation "Duke" off the coast of Tam Quan, RVN in October 1966, and lifts to Cam Ranh Bay, Tuy Hoa, and Qui Nhon. She also spent considerable time in support of Naval Support Activity at Da Nang carrying general cargo, ammunition, troops, and lubricants.

At Vung Tau she relieved Sutter County (LST-1150) on 4 February 1967 for "Market Time" operations serving as a base of operations for Coast Guard cutters and Navy Swift Boats and providing them necessary supplies and repairs. She was relieved 4 March by Pitkin County (LST-1062), and departed Vietnamese waters for Hong Kong, and Manila.

Park County returned to Da Nang 31 May and resumed operations with the Naval Support Activity. On 22 September she sailed to Guam and got underway 19 November for Yokosuka, Japan. From Yokosuka she conducted amphibious training operations until 2 December when she returned to Da Nang via Taiwan and Subic Bay, arriving 5 January 1968.

At Da Nang she was assigned to the Da Nang-Cua Viet shuttle run. On 29 February she began more "Market-Time" operations. Park County continued her support of Vietnam operations until 13 December when she got underway for Guam for extensive overhaul. Leaving Guam 18 April 1969 she returned to Da Nang via Buckner Bay and Subic Bay, arriving 11 July.

Into 1970 Park County continues a vital service to the U.S. Navy.