The drawing shows Brulé chief Conquering Bear and where he was hit by a bullet. Muzzel fire from four guns are shown. The head of a man wearing a fatigue cap indicates U.S. soldiers. The thirty dots is a reference to the casualties of the whites known by the Lakotas.
Government Printing Office
Mallery, Gerrick: ”Pictographs of the North American Indians.” Fourth Annual Report of the Bureau of Ethnology, 1882-’83.  Smithsonian Institution. Washington, 1886. GPO