LST-1146 was laid down on 10 February 1945 at Seneca, III., by the Chicago Bridge & Iron Co.; launched on 11 May 1945; sponsored by Mrs. Margaret L. Hecht, Jr.; and commissioned on 30 May 1945, Lt. Warren A. Gushing, Jr., in command.
Following World War II, LST-1146 performed occupation duty in the Far East until mid-November 1945. After occupation duty, LST-1146 operated off the west coast of the United States for the next five years, principally occupied with resupply missions for Alaskan ports. During the Korean War, her resupply efforts were shifted to Korean ports. On 1 July 1955, she was redesignated Summit County (LST-1146) (q.v.) after counties in Colorado, Ohio, and Utah. From 1965 into 1969, Summit County saw extensive service in the Vietnam theater. She was transferred to the Maritime Administration in December 1969 and assigned to the Pacific Reserve Fleet at Suisun Bay, Calif. Summit County was sold to Ecuador on 1 November 1976.
LST-1146 earned one battle star for Korean War service and four battle stars for the Vietnam War.