While the Fort Peck Reservation is inhabited primarily by Assiniboine and Sioux people, a recent survey suggests that approximately 500 Indians from other tribes live within reservation boundaries as well. These people include the Chippewa, Cree, and Teton Sioux. According to the board's discretion, a secretary-accountant may be appointed either from the board's membership or from the tribal membership. Board members preside over nine business committees, each dealing with broad areas of tribal policy and business management. The reservation lies within a region in which the economic base is almost entirely agricultural.
Important crops grown in the area include cereals and feed grains, hay silage, and grasses.
Dryland farming, mostly in spring wheat, accounts for about 75 percent of all harvested acreage. Eight grain elevators are located on the reservation. Currently, the tribe is attempting to update its irrigation system, which was constructed in 1908. Located along the Missouri River Valley between the towns of Frazer and Wolf Point, this irrigation system services approximately 18,500 acres. Only about 22 percent of these irrigated lands are operated by Indians.