Complex sentence: Red Dog's heritage was a mix of Sioux and Assiniboine; he was a member of the Lakota tribe, and grew up on Fort Peck Reservation in Poplar, in northeast Montana.
Split into simpler sentences: Red Dog's heritage was a mix of Sioux and Assiniboine. He was a member of the Lakota tribe, and grew up on Fort Peck Reservation in Poplar, in northeast Montana.