The Tribal Government has control over most activities inside of the reservation borders. The Tribe has its own court system, jail, and treatment center. In addition to the Tribal Government, there are also city and county governments, as well as a Sisseton Wahpeton Sioux Council. The Tribal Headquarters are located in Poplar, widely viewed as the capital of the Reservation. The Bureau of Indian Affairs has the Fort Peck Agency located in Poplar.
