Oahe Dam Oahe Dam The Oahe Dam is a large earthen dam on the Missouri River, just north of Pierre, South Dakota, United States. The dam creates Lake Oahe, the fourth largest man-made reservoir in the United States. The reservoir stretches up the course of the Missouri to Bismarck, North Dakota. The dam's power plant provides electricity for much of the north-central United States. It is named for the Oahe Indian Mission established among the Lakota Sioux in 1874. The project provides flood control, Hydropower generation, irrigation, and navigation benefits. Oahe Dam is one of six Missouri River mainstem dams, the next
Oahe Dam earth main dam reached its full height in October 1959. It was officially dedicated by President John F. Kennedy on August 17, 1962, the year in which it began generating power. The original project cost was $340,000,000. Tours of the powerplant are given daily, Memorial Day through Labor Day. As a result of the dam's construction the Cheyenne River Indian Reservation lost bringing it down to today. Standing Rock Reservation lost leaving it with . Much of the land was taken by eminent domain claims made by the Bureau of Reclamation. Over and above the land loss, most of the