The Fort Peck Reservation in northeast Montana is home to the Assiniboine and Sioux tribes (Dakota/Nakota). It covers most of Roosevelt County and parts of Valley, Daniels, and Sheridan counties. It is approximately 110 miles long and 50 miles wide and is characterized by glacially formed landscapes that include floodplains and rolling hills. The area is rich in wildlife and has a climate of warm summers and cold winters, with Wolf Point and Poplar as its largest towns.