Tongue River Dam
The earthen dam was constructed in the river canyon in 1939, with a height of 91 feet and a length at its crest of 1824 feet. It impounds Montana's north-flowing Tongue River for flood control and irrigation water storage. The dam and reservoir are owned and operated by the Montana Department of Natural Resources and Conservation.
The 12-mile-long riverine reservoir it creates has a normal water surface of 5.5 square miles, a maximum capacity of 150,000 acre-feet, and normal storage of 69,400 acre-feet. Recreation includes boating, fishing (for bass, crappie, walleye and northern pike), camping (at more than 150 campsites), etc., in the Tongue River Reservoir State Park. For white-water rafters the Tongue is a Class I river from the Dam downstream (northward) to its confluence with the Yellowstone River.