The Crow Native name is Absaroka (or Apsaslooka) Siouan for “bird people.” Their name among Europeans became that of the well-known bird and is pronounced the same way. Early in their history, they split off from another Siouan-speaking people, the HIDATSA, of the upper Missouri in what is now North Dakota because of a dispute over buffalo.
The Crow then migrated farther upriver, to the Yellowstone River at the foot of the Rocky Mountains, territory now part of southern Montana and northern Wyoming. The Crow who settled north of the Yellowstone toward the Musselshell River became known as the Mountain Crow because of the high terrain. Those who ranged to the south along the valleys of the Big Horn, Powder, and Wind Rivers came to be called the River Crow.