North American Plains Indian people living mostly in North Dakota, U.S. Their name is probably of French derivation.
The Mandan language, which is sun dance and the bear ceremony, a healing and war-preparation rite. They had age-graded warrior societies as well as shamanistic and women's societies. Artists depicted heroic deeds on buffalo robes. George Catlin portrayed Mandan life and people in a series of paintings. According to him, they called themselves Seepohskahnumahkahkee, meaning "People of the Pheasant." By the mid-19th century the Mandan, reduced by smallpox, were removed to North Dakota's Fort Berthold Reservation, where they live with the {{link=Hidatsa">Hidatsa and the Arikara as the Three Affiliated Tribes. Some 350 people claimed sole Mandan descent in the 2000 U.S. census.