The Fort Peck Lake, located in the eastern prairie region of Montana, United States, runs 134 miles with a surface area of 245,000 acres.
The lake lies in the eastern prairie region of Montana approximately 140 miles (230 km) east of Great Falls and 120 miles (190 km) north of Billings, reaching into portions of six counties. 134 mi (216 km) 245,000 acres (99,000 ha) Montana,
United States 
