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,
Big Bend Dam 47 crosses over the dam, connecting Lyman and Buffalo Counties. Big Bend Dam is located approximately north of I-90, and approximately southeast of Pierre. The next dam upstream is Oahe Dam, near Pierre, and the next dam downstream is Fort Randall Dam, near Pickstown. The construction of the dam resulted in the dislocation of people on the Crow Creek and Lower Brule Reservations. The flooding of the land for the reservoir also resulted in the loss of limited plant life resources used by these people for food and medicine. A monument at Big Bend Dam dedicated in 2002, the Spirit