By the 1770s, the Teton Sioux had overrun the Arikara, or Ree, on the Missouri River and made it as far west as the Black Hills, where they quickly ousted the Kiowa and the Crows. Over the next hundred years the Sioux continued to expand their territory, eventually forcing the Crows to retreat all the way to the Bighorn River more than two hundred miles to the west, while also carrying on raids to the north and south against the Assiniboine, Shoshone, Pawnee, Gros Ventre, and Omaha.