This is probably one of two versions of Spotted Elk Sharp exhibited in Washington, DC's Cosmos Club Special Exhibition of Indian Portraits Painted from Life in December, 1901. (the other is #162) It was this version that inspired Sharp to make an etching of the famous man, (seerelated image 223a)

Sharp painted several later versions of this chief  between 1905 and 1906, one of which is #222 that was donated to the Smithsonian Institution in later years. The sitter in all these portraits was Dick Spotted Elk (Hehaka Gleska), son of the famous Chief Spotted Elk/Big Foot who died at the Wounded Knee Massacre in 1890.