From Bury My Heart at Wounded Knee: An Indian History of the American West, page 200:

After the fight on the Rosebud, the chiefs decided to move west to the valley of the Greasy Grass (Little Bighorn). Scouts had come in with reports of great heads of antelope west of there, and they said grass for the horses was plentiful on the nearby benchlands. Soon the camp circles were spread along the west bank of the twisting Greasy Grass for almost three miles. No one knew for certain how many Indians were there, but the number could not have been smaller than ten thousand people, including three or four thousand warriors. "It was a very big village and you could hardly count the teepees," Black Elk said.

Farthest upstream toward the south was the Hunkpapa camp, with the Blackfoot Sioux nearby. The Hunkpapas always camped at the entrance, or at the head end of the circle, which was the meaning of their name. Below them were the Sans Arcs, Minneconjous, Oglalas, and Brulés. At the north end were the Cheyennes.