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,
Lake Sakakawea Lake Sakakawea Lake Sakakawea is a large reservoir in the north central United States, impounded by Garrison Dam, a U.S. Army Corps of Engineers dam located in the Missouri River basin in central North Dakota. Named for the Shoshone-Hidatsa woman Sakakawea, it is the largest man-made lake in the State of North Dakota, the second largest in the United States by area after Lake Oahe, and the third largest in the United States by volume, after Lake Mead and Lake Powell. The lake is located about from the state capital of Bismarck; the distance by the Missouri River is about