The Sioux Indians Author:Sonia Bleeker The Sioux Indians, Hunters and Warriors of the Plains. They were latecomers into this far western territory of North and South Dakota. Tribes of the Sioux Indians first began to move into the Great Plains from about 1750 to 1775--just before the American Revolution. It seemed a time of general unrest among the Indian people, as well as among ... more »non-Indians. Hard pressed by the Chippewa Indians, the Sioux were forced to move to the Great Plains. They took a liking to the new land and the the free, adventurous life of buffalo hunters and warriors.« less