I haven't done enough research to know exactly which Native American chief is portrayed in this wonderfully expressive small ink and watercolor drawing/painting, but do know that "Blood Indians" refers to the Kainai, or Káínawa of southern Alberta, Canada, one of three nations (along with the Siksika and Peigan) comprising the Blackfoot Confederacy. It seems possible that this portrait is of Mi'k ai'stoowa (Red Crow), who signed Treaty 7, an agreement with the U.S. federal government in 1881 which effectively put an end to many traditional ways of life, including bison hunting, leading to what became known as “starvation winter in 1883-4. 

6 1/8" x 4 1/8". I am not certain the age of this piece, which in many ways feels quite contemporary, but I do believe is fairly old. It appears to be signed Walker at lower right. The paper may be an old book page, with an embossed frame. Age toning and some scattered stains around the perimeter, but overall very good condition.