Counties in Colorado, Ohio and Utah.
(LST-1146: dp. 3,960; l. 328'; b. 50'; dr. 11'2"; s. 11.6 k.; cpl. 119; trp. 147; a. 8 40mm.; cl. LST-542)
LST-1146 was laid down on 10 February 1945 by the Chicago Bridge and Iron Co., Seneca, 111.; launched on 11 May 1945; sponsored by Mrs. M. L. Hecht, Jr.; and commissioned on 30 May 1945, Lt. Warren A. Gushing, USNR, in command.
On 4 June, LST-1146 shifted from New Orleans to Mobile, Ala., for propeller repairs and then to Galveston, Tex. Her shakedown cruise was held in Galveston Bay from 10 to 20 June, and she returned to New Orleans for repairs. She then loaded supplies, ammunition, and 92 passengers and departed for Gulfport on the 30th to load deck cargo. Seven hundred tons of pontoon cargo, destined for Guam, M.I., were loaded, and LST-1146 sailed for Panama on 5 July. She arrived at Coco Solo, C.Z., on 11 July; disembarked her passengers; and continued to Hawaii the next day. The ship arrived in Pearl Harbor on 2 August. On 1 September, she steamed westward and, after calls at Eniwetok, Guam, Saipan, and Okinawa, arrived at Sasebo, Japan, on 2 November. She moved to Yokosuka ten days later and on the 19th began her return voyage to the United States, via Guam and Pearl Harbor.
LST-1146 arrived at Seattle on 4 January 1946 and began an extended yard period. When again ready for sea, she moved down the coast and operated out of San Diego from June 1946 to 24 May 1947. At that time she moved to Port Hueneme, loaded supplies, and joined five other ships to form the Navy's annual resupply expedition to Point Barrow, Alaska. After calling at Seattle on 12 June, the ships proceeded to Kodiak, Adak, and Attu. LST-1146 returned to Seattle from 14 July to 1 August for additional supplies and continued operating in Alaskan waters from 15 August to early September 1947 when she returned to San Diego and began local operations. The ship operated out of San Diego for the next four years and each summer she participated in the supply run to Alaska.
LST-1146 stood out of San Diego on 19 October 1951, en route to the Korean war zone. After port calls at Pearl Harbor and Yokosuka, she arrived at Inchon on 28 December 1951. Operating from Yokosuka until April 1952, the ship carried troops and supplies to various Korean ports. On 7 April, she departed Japan for her homeport of San Diego and arrived there on 10 May 1952.
She made resupply runs to Alaska that summer and again in 1953. After returning to San Diego from her last Alaskan run on 10 September 1953, she prepared for another tour in the western Pacific that lasted from 20 October 1953 to 27 April 1954. In July 1955 LST-1146 was officially named Summit County in honor of counties in Colorado, Ohio, and Utah. She deployed to the Far East again from 4 January to 5 October 1956; 9 January to 17 July 1958; and from 31 January to 8 June 1959. In 1960, Summit County operated in the Hawaiian Islands from 19 March to 16 July.
Summit County deployed to Hawaii on 9 April 1962 and, from 3 October until returning to San Diego on 27 November, she participated in the nuclear tests in the central Pacific. She served in Hawaii again from 27 July until late December 1964. On 10 December 1965, the LST stood out of San Diego on a deployment that took her to Vietnam and the combat zone. She arrived at Guam, M.I., on 8 January 1966 en route to Danang, via Subic Bay, P.I. She arrived there on 24 January and began shuttling supplies to Chu Lai. On 11 March she ran over a coral pinnacle which flooded her engine room. The ship was towed to Sasebo for repairs which lasted until 16 May. She then returned to South Vietnam and resumed her former shuttle duties. Summit County completed her mission in Vietnam on 24 July and, after port calls at Subic Bay, Hong Kong, and Pearl Harbor, returned to San Diego on 16 September.
Summit County had a pre-overhaul and overhaul period that lasted from 1 January to 5 May 1967. After refresher training, she participated in amphibious training exercises until 4 August when she prepared for another tour in the Far East. She departed San Diego on 12 September and arrived at South Vietnam on 16 November. She left the operations area on 16 December 1967 for Keelung, Formosa, for a period of rest and relaxation. She sailed from there on 4 January 1968 for Subic Bay and thence back to Vietnam. Summit County participated in Operation "Market Time" from 17 January to 1 March. Then she was relieved by Park County (LST-1077). She had an availability period at Yokosuka, from 20 March to 12 April, and began the journey back to the United States, via Pearl Harbor. She arrived at San Diego on 11 May and operated from there the remainder of the year and into the fall of 1969 when it was decided that she would be inactivated.
Summit County was returned to the Maritime Administration in December 1969 and into March 1975 was attached to the Pacific Reserve Fleet and berthed at Suisun Bay, Calif.
Summit County received one battle star for Korean service and three for service in Vietnam.