Rancher H. H. Halsell sold the land one mile west of Fort Supply to territorial legislator James P. Gandy.

The Flood Control Act of 1936 provided for construction of a dam and reservoir one mile southeast of the town in the valley of Wolf Creek.

Work began on the largest earthen dam in the United States of America in October 1938 and Fort Supply Lake was completed in May 1942.

The United States Army Corps of Engineers administers Fort Supply Lake and the adjacent wildlife and recreation area.

On December 6, 1988, the State of Oklahoma located a new prison, William S. Key Correctional Center, on the grounds of nearby former Fort Supply.

Agriculture and employment at these state institutions form the economic base of the community of Fort Supply.

The nearby Cooper Bison Kill Site is on the National Register of Historic Places listings in Harper County, Oklahoma.