Mandan, Hidatsa, and Arikara Nation

The Mandan, Hidatsa, and Arikara Nation (MHA Nation), also known as the Three Affiliated Tribes (Mandan: Miiti Naamni; Hidatsa: Awadi Aguraawi; Arikara: ačitaanu' táWIt), is a federally recognized Native American Nation resulting from the alliance of the Mandan, Hidatsa, and Arikara peoples, whose Indigenous 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 (1851) and subsequent taking of land, the Nation's land base is currently approximately 1 million acres located in Fort Berthold Reservation in northwestern North Dakota. The Tribe reported a total enrollment of 16,986 enrolled members of the Mandan, Hidatsa and Arikara Nation as of April 2022.^[1] Nearly 5,600 live on the Fort Berthold Indian Reservation; others live and work elsewhere.^[1]