Authorization: Authorized as a part of the McClellan-Kerr Arkansas River Navigation System in the River and Harbor Act approved July 24, 1946, Project Document HD 758, 79th Congress, 2d Session. Section 1117 of the Water Resources Development Act of 1986, Public Law 99-662, authorized the Cherokee Nation of Oklahoma to design and construct hydroelectric generating facilities at W. D. Mayo Lock and Dam.

Location: On the Arkansas River at navigation mile 319.6, about 9 miles southwest of Fort Smith, Arkansas, in LeFlore and Sequoyah Counties, Oklahoma.

Status: Complete.

Purpose: Navigation, fish and wildlife, and recreation.

History of Construction: Construction began in May 1966. Closure was completed on October 15, 1970, and the project was placed in useful operation. The lock and dam became operational for navigation in December 1970.

Type of Structure: The 7,400-foot-long dam consists of a low concrete apron and sill surmounted by tainter gates separated by 10-foot concrete piers. The gates are operated with machinery constructed on the piers. Twelve 60- by 21-foot tainter gates are provided for the structure.

Lock:  The lock has a 110- by 600-foot chamber of the single-lift type with miter gates.  The lock has a 20-foot normal lift and 22-foot maximum lift.