The Northern Plains--that vast grassland extending from the Mississippi and Red Rivers westward to the Rocky Mountains, and from the valley of the Saskatchewan River in Canada southward to the Platte in Nebraska and Wyoming--is the home of a score of Indian tribes--the Algonquian-speaking Arapaho, Cheyenne, Gros Ventres, Plains Cree, Plains Ojibwa, and the three Blackfoot tribes; the Siouan-speaking Assiniboine, Crow, Hidatsam Mandan, and the seven divisions of the Dakota or Sioux; the Caddoan-speaking Arikara, and the small Athapascan-speaking tribe of Sarsi.

No other Indians are more widely known than are those of this region. They and their deeds as big game hunters, warriors, and horsemen have been most frequently portrayed in the paintings of George Catlin, Frederic Remington, and Charles M. Russell; in Wild West Shows from the days of Buffalo Bill to current TV dramas, and in countless books and articles of fact and of friction.