Dancer of the Hidatsa Dog Society, aquatint by Karl Bodmer, 1834.—Courtesy of the Rare Book Division, the New York Public Library, Astor, Lenox and Tilden Foundations
North American Plains Indian people living mainly on Fort Berthold Reservation in North Dakota, U.S. They speak a Siouan language. They were mistakenly identified as a group known to French trappers as Gros Ventres; as a result, the Hidatsa were sometimes called the Gros Ventres of the Missouri. Originally, the Hidatsa (whose name means people of the willow) lived on the upper Missouri River in semipermanent villages. They raised corn, beans, and squash and hunted bison. Hidatsa social organization included age-graded military societies; there were also various clans based on maternal descent. The sun dance was the major religious ceremony. Together with the Mandan, with whom they had peaceful relations for more than 400 years, they exchanged traditional goods with European traders for guns, knives, and other items. In the mid-1800s disease and war with the Dakota (Sioux) sharply reduced their number. Together the Mandan, the Arikara, and the Hidatsa form the Three Affiliated Tribes. Hidatsa descendants numbered some 1,500 in the early 21st century.