Lower Granite Lock and Dam was authorized by the River and Harbor Act of 1945. The project includes a dam, a navigation lock, powerhouse, a fish ladder and associated facilities. It provides hydropower, navigation, flood risk management, fish and wildlife habitat, recreation and incidental irrigation. The dam, located on the Snake River, is about 3,200 feet long with an effective height of 100 feet. It is a concrete gravity type, with an earthfill right abutment embankment.

Recreation areas along the project’s reservoir offer a variety of recreation opportunities such as fishing, swimming, picnicking, boating, hunting, hiking and camping.