The
Fort Belknap Indian Reservation is a semi-autonomous
Native American-governed territory covering 1,014.064 sq mi (2,626.415 km²), and is located in north central Montana. This includes the main portion of their homeland, as well as
off-reservation trust land. It is shared by two Native American tribes, the
A'aninin (
Gros Ventre) and the
Nakota (
Assiniboine). Its largest city is
Fort Belknap Agency, at the reservation's north end. This is just south of the city of
Harlem across the
Milk River.