Begun in 1948 and opened in 1962, the dam creates Lake Oahe, the fourth-largest man-made reservoir in the United States.

In September and October 1804, the Lewis and Clark Expedition passed through what is now Lake Oahe while exploring the Missouri River.

The Oahe Dam was authorized by the Flood Control Act of 1944, and construction by the United States Army Corps of Engineers began in 1948.

It was officially dedicated by President John F. Kennedy on August 17, 1962, the year in which it began generating power.

The regions where the populations were resettled had soil with a higher clay content, and resources such as medicinal plants were less prevalent.