Three Affiliated Tribes of the Fort Berthold Reservation

The Mandan, Hidatsa, and Arikara Nation (MHA Nation), also known as the Three Affiliated Tribes, is a Native American Native American Nation resulting from the alliance of the Mandan, Hidatsa, and Arikara peoples, whose native lands ranged across the Missouri River basin extending from present day North Dakota Through western Montana and Wyoming.

After the signing of the Fort Laramie Treaty and subsequent taking of land, the Nation's land base is currently approximately 1 million acres located Fort Berthold Reservation in northwestern North Dakota. The Tribe reported a total enrollment of 15,309 registered tribe members in March 2016. Nearly 6,000 live on the reservation; others live and work elsewhere.

Membership (Citizenship) is derived from the 1936 Indian Census roll of the Three Affiliated Tribes. In 2010 the tribal council passed amendments specifying "blood quantum," or minimum amounts of tribal ancestry to qualify individuals for membership and for candidates for public office. Individuals must have at least 1/8 Mandan, Hidatsa, or Arikara ancestry (the equivalent of one full-blooded great-grandparent) to become an enrolled member of the MHA Nation and 1/4 ancestry to serve in elected office.

The Tribal Business Council consists of six Segment Representatives and a Chairman. Each member's term lasts 4 years, and there are no term limits. The Tribal Business Council holds Regular Meetings on the second Thursday of each month, and sub-committees meet at different times throughout the month.

The Mandan are a Native American tribe currently part of the Three Affiliated Tribes of North Dakota. At the height of their historic culture, the Mandan were prosperous and peaceful farmers and traders, noted for their excellent maize cultivation and crafting of Knife River flint. They built earth lodges, and made villages of considerable technical skill, and cultivated many varieties of maize. They were a more sedentary people than other, more nomadic tribes of the Great Plains.

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