Fort Belknap Indian Reservation
|— Reservation —|
|Established||June 1, 1888 (Treaty)|
|• Body||Ft.Belknap Tribal Council|
|• President||Tracy King|
|• Vice-President||Mel L. Adams Doney|
|• Total||2,626.415 km2 (1,014.064 sq mi)|
|Population (2010)Enrolled tribal members|
|• Density||1.1/km2 ( 2.8/sq mi)|
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.
Established in 1888, the reservation is what remains of the vast ancestral territory of the Blackfeet and Nakoda Nations. The A'aninin, as members of the Blackfoot Confederacy, and the Nakoda Nation signed the Fort Laramie treaties of 1851 and 1855 with the United States Government establishing their respective territories within the continental United States. The Fort Belknap Reservation is part of what remains of these two nations' ancestral territory that included all of central and eastern Montana and portions of western North Dakota. The Blackfeet, and Fort Peck Indian Reservations are also part of these territorial boundaries.
A 12-bed hospital within the reservation has been replaced with a 6-bed infirmary, that began to be occupied on May 18, 1998. As part of treaties and agreements between the U.S. government and the Native American tribes, health services are to be provided to Native American people. This was in exchange for the many lands given up by the Native American people in return for things such as the railroad, homesteading, roads, reservoirs, and other installations. The establishment of IHS (Indian Health Services) did not occur until 1955, the concepts of self-dependency and determination and tribal sovereignty having been a longstanding tradition.
The A'aninin, (meaning the White Clay People) believe that they were made from the White Clay that is found along the river bottoms in A'aninin Country. Early French fur trappers and traders named this tribe "Gros Ventre" because other tribes in the area referred to them as “The Water Falls People.” The sign for water fall is the passing of the hands over the stomach and the French though the Indians were saying big belly so they called them "Gros Ventre" – meaning “big belly” in the French language.
The Nakoda (meaning the Generous Ones) split with the Yanktonai Sioux in the seventeenth century and migrated westward onto the northern plains with their allies, the Plains Cree. The Chippewa called the Nakoda "Assiniboine", which is a Chippewa word meaning “One who cooks with stones”. The Nakoda are located on both the Fort Belknap and Fort Peck Indian Reservations in Montana and on several reserves in Saskatchewan and Alberta.
The A'aninin and Nakoda were nomadic hunters and warriors. They followed the buffalo which provided them with all the necessities of life. Their food, clothing and teepees all came from the buffalo. The buffalo was the Indian staff of life and the Nakoda and A'aninin and other plains tribes lived a good life with the buffalo. The last wild herd of buffalo in the continental United States in the nineteenth century roamed between the Bear Paw Mountains and the Little Rocky Mountains in the lush Milk River valley.
Today, the two tribes are united as one government called the Fort Belknap Indian Community. Together, the tribes have formed and maintained a community that has deep respect for its land, its culture, and its heritage. Fort Belknap derives its name from the original military post that was established on the Milk River, one mile southwest of the present town of Chinook, Montana. The Fort, named for William W. Belknap, who was the Secretary of War at that time, was a military fort combined with a trading post. It became a Government agency for the A'aninin and Nakoda Tribes living in the area.
In literature 
The novel, Winter in the Blood, is set here.
Notable A'aninin 
- James Welch (1940 – August 4, 2003) was a award-winning A'aninin author and poet.
- Bein Es Kanach (Red Whip) was a famous A'aninin chief.
- Theresa Lamebull (1896 – August 2007) was a Supercentenarian believed to have been be the oldest living member of the A'aninin Tribe of Montana and possibly the oldest Native American ever recorded.
- George Horse-Capture (1937 – 2013) was an A'aninin anthropologist and author, who became a curator at the Plains Indian Museum and the National Museum of the American Indian.
- "Yellowstone bison return to tribal land". Great Falls Tribune. 2012-03-21. Retrieved 2012-03-23.
- Fort Belknap Reservation and Off-Reservation Trust Land, Montana
- Film adaptation of the novel Winter in the Blood by James Welch