Three Affiliated Tribes

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Three Affiliated Tribes

Native American tribal group

Also known as: MHA Nation

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July 16, 2026

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The Three Affiliated Tribes are a Native American tribal group formed by the merger of the Mandan, Hidatsa, and Arikara nations. These tribes, originally living in semipermanent villages along the Missouri River in present-day North Dakota, faced devastating epidemics, particularly smallpox, in the late 18th and early 19th centuries. To ensure their survival, the Mandan survivors merged with the Hidatsa, and later the Arikara joined them, leading to their legal unification as the Three Affiliated Tribes.123

Despite this merger, the distinct ethnic identities of the Mandan, Hidatsa, and Arikara have persisted, with most members continuing to refer to themselves by their original tribal names. In the mid-20th century, the construction of the Garrison Dam flooded a significant portion of their reservation, impacting their traditional agricultural lands and forcing relocation. In response to economic challenges, the tribes have developed enterprises such as buffalo ranching and casinos, while also focusing on cultural revitalization and the preservation of their languages.1234

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Arikara
…coalesced, becoming known as the Three Affiliated Tribes (or MHA Nation), and a reservation was created for them at Fort Berthold, North Dakota. By 1885 the Arikara had taken up farming and livestock production on family farmsteads dispersed along the rich Missouri River bottomlands.
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…coalesced, becoming known as the Three Affiliated Tribes (or MHA Nation), and a reservation was created for them at Fort Berthold, North Dakota. By 1885 the Arikara had taken up farming and livestock production on family farmsteads dispersed along the rich Missouri River bottomlands.
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Hidatsa
…Arikara, collectively known as the Three Affiliated Tribes, have lived together on what is now the Fort Berthold Reservation in North Dakota.
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…Arikara, collectively known as the Three Affiliated Tribes, have lived together on what is now the Fort Berthold Reservation in North Dakota.
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Mandan
…eventually became known as the Three Affiliated Tribes (also called the MHA Nation).
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…eventually became known as the Three Affiliated Tribes (also called the MHA Nation).
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Minot
…Minot is home to the Three Affiliated Tribes (Mandan, Hidatsa, and Arikara). The International Peace Garden, on the U.S.-Canadian border, is about 100 miles (160 km) northeast of the city. The Upper Souris and J. Clark Salyer national wildlife refuges are nearby. Inc. 1887. Pop. (2000) 36,567; (2010) 40,888.
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…Minot is home to the Three Affiliated Tribes (Mandan, Hidatsa, and Arikara). The International Peace Garden, on the U.S.-Canadian border, is about 100 miles (160 km) northeast of the city. The Upper Souris and J. Clark Salyer national wildlife refuges are nearby. Inc. 1887. Pop. (2000) 36,567; (2010) 40,888.
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Native American Self-Names
…taken a new name, the Three Affiliated Tribes. Yet, even as they worked in concert politically, the original groups created separate ethnic enclaves; well into the early 21st century, most members of this tribe referred to themselves as Mandan, Hidatsa, or Arikara or used a hyphenated ethnicity (e.g., Mandan-Hidatsa). Clearly,…
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…taken a new name, the Three Affiliated Tribes. Yet, even as they worked in concert politically, the original groups created separate ethnic enclaves; well into the early 21st century, most members of this tribe referred to themselves as Mandan, Hidatsa, or Arikara or used a hyphenated ethnicity (e.g., Mandan-Hidatsa). Clearly,…
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