Garrison Dam

Garrison Dam is an earth-fill embankment dam on the Missouri River in central North Dakota. At over two miles (3 km) in length, it is the fifth-largest earthen dam in the world, constructed by the U.S. Army Corps of Engineers from 1947-53. The reservoir impounded by the dam is Lake Sakakawea, which extends to Williston and the confluence with the Yellowstone River, near the Montana border. Garrison Dam is located between Riverdale and Pick City, named after the town of Garrison, directly north of the dam, across the reservoir. The dam is approximately midway between Bismarck and Minot, about 10 miles (16 km) west of U.S. highway 83. Hydropower turbines at Garrison Dam have an electric power generating nameplate capacity of 583.3 megawatts. Average production of 240 megawatts serves several hundred thousand customers.