The setting of When the Legends Die is the western United States, in particular Colorado. The main character, Thomas Black Bull, is a member of the Ute Native American tribe. The novel has Thomas living in the small town of Pagosa. He also lives in the wilderness (sometimes with both parents, sometimes with just his mother, and sometimes completely alone) and at a Native American reservation school.
Just as Legends has its setting in a number of specific locations, the protagonist of the novel goes through some name changes. He is given the name Little Black Bull at birth by his parents. When a white minister baptizes him, he is given the name Thomas Black Bull. Nearing his teenage years, he renames himself Bear's Brother and later, while popular on the rodeo circuit, his fans nickname him Killer Tom.
In short, in When the Legends Die, a change in setting often signals a change in name/identity for the protagonist.