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
Toston Dam Toston Dam Toston Dam is a hydroelectric gravity dam located on the Missouri River in Broadwater County, Montana. The dam is long and high, and generates 10 megawatts of power. The dam is a "run-of-the-river" dam because it can generate electricity without needing to store additional water supplies behind the dam. The dam is named after the town of Toston, Montana, which is just away. A $1.12 million dam was originally proposed in 1935. This project never was built. A smaller dam, whose construction would cost $900,000, was proposed in 1938, and the Montana State Water Conservation Board sought Public