Extending for two miles, when built this earth-fill embankment dam on the Missouri River was the fifth-largest earthen dam in the world. Constructed by the U.S. Army Corps of Engineers, the reservoir impounds Lake Sakakawea and extends west to Williston, and the Missouri’s confluence with the Yellowstone River near the Montana border. Construction of the dam entailed displacement of many members of the Three Affiliated Tribes from their traditional river bottomlands and from several culturally important communities that were inundated by creation of the lake, a tragedy from which the Mandan-Hidatsa-Arikara people have never healed. Paul VanDevelder chronicles many of the events associated with this culturally devastating event in Coyote Warrior: One Man, Three Tribes, and the Trial That Forged a Nation (2004).
Responding to the federal Pick-Sloan Missouri Basin Program authorized in 1944 for water conservation, construction began in 1947 and the dam’s embankment was enclosed in April 1953. President Dwight D. Eisenhower dedicated the dam two months later. Hydropower turbines at Garrison Dam have an electricity-generating capacity of 583 megawatts. In addition to power generation and recreational uses, the Garrison Dam and Lake Sakakawea continue to have lingering impacts on native people, downstream water resource management, and the natural environment, evidenced by the McClusky Canal diversion channel and the U.S. Army Corps of Engineers’ planned community of Riverdale.