Garrison Dam Tribes. Construction on the $300-million dam project began in 1947, and its embankment was enclosed in April 1953. The dam was dedicated by President Eisenhower two months later. The Corps of Engineers completed earthwork in the fall of 1954. Garrison Dam is one of six Missouri River Main stem dams operated by the U.S. Army Corps of Engineers, Omaha District. The dam upstream of Garrison Dam is Fort Peck Dam (near Fort Peck, Montana). The dams downstream of Garrison Dam are: Oahe Dam (near Pierre, South Dakota), Big Bend Dam (near Fort Thompson, South Dakota), Fort Randall Dam (near Pickstown,
Hoover Dam Police Security Zone encompasses around Hoover Dam and Lake Mead; before the opening of the bypass, this included of U.S. Highway 93 (US 93). Vehicles had to pass through inspection checkpoints, located on US 93 north of the dam in Nevada, and south of the dam in Arizona, before crossing. With the opening of the bypass, traffic patterns changed dramatically. Through traffic no longer goes through a checkpoint on either side of the river. On the Nevada side, the dam road now branches off US 93 before the checkpoint, which remains in operation to screen dam visitors. On the Arizona side,