This, stylistically and by the design of the signature, appears to be an early portrait and was probably part of the initial, large sale to Mrs. Hearst that occurred in December 1901. It is nearly identical to a second version sold to Joseph Butler earlier in 1901. (related image, #337)
Both portraits were probably painted from a photograph taken at the Babcock Store at Crow Agency in about 1901. (See related image, #125a and Fenn, 2007, 149)