Hidatsa Indians, a tribe of the Siouan language family. They are sometimes called the Minitari or Gros Ventres. The Lewis and Clark expedition (1804–06) found the Hidatsa Indians in three villages at the junction of the Knife and Missouri rivers, in what is now North Dakota. The Hidatsa lived by farming and hunting. After the smallpox epidemic of 1837 had reduced their numbers they lived with the Mandan and Arikara Indians. Fort Berthold Reservation was created for the three tribes in 1880. Through intermarriage over the years, the tribes have all but lost their separate identities.