Little Goose Lock and Dam, a hydroelectric, concrete gravity dam in Washington State on the Snake River. The structure and three generators were completed in 1970; three additional generators were installed in 1978. Generating capacity is 810 megawatts, with an overload capacity of 932 MW. The spillway has eight gates and is 512 feet (156 m) long. Little Goose Dam is part of the Columbia River Basin system of dams. Its single lift navigation lock is 86 ft. wide and 668 ft. long.