Thomas Black Bull
- The main character and protagonist of the novel, Tom was raised in the traditional Ute Native American ways, in the wilderness. After both his parents die, he experiences several adventures before becoming a famous bronco rider.
in-depth analysis of Thomas Black Bull.
- Tom's mother, a Ute Indian. Wise, courageous, intelligent, and strong-willed, Bessie teaches her son Tom about all the old Ute traditions and customs.
in-depth analysis of Bessie.
George Black Bull
- Tom's father. George Black Bull is an honest and hard-working man who loves his family. He strives to educate his son about how to survive in the wilderness after he must flee town for killing a thief who repeatedly stole his hard-earned money.
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- A member of the Ute tribe, greedy old Blue Elk lives in Piedra Town. Blue Elk lies and cheats his own people for monetary gain, while claiming to work for their good.
in-depth analysis of Blue Elk.
- The preacher baptizes Tom and later feels responsible for his development.
- A stocky thirty-year-old Ute man. Benny works as a vocational instructor in the carpenter shop on the reservation.
- A tracker who assists Benny in locating Tom after his escape.
Albert Left Hand
- Albert Left Hand owns a little band of sheep on the flats at the northern edge of the reservation. In need of a helper, he hires eleven-year-old Tom to help.
- A gambler and an alcoholic, Red owns a ranch in New Mexico. He instructs young Tom as a bronco rider. Tom travels with him to many shows throughout the southwestern United States. He continually exploits Tom for his ability to win him gambling money.
- A retired bronco rider, the illiterate Mexican man Meo is Red's cook. Tom and Meo become friends, as they understand each other's circumstances.
- A Ute friend of Tom's father. Charley is a member of the council on the reservation.
Frank No Deer
- A mixed-blood Native American from a reservation in New Mexico. Frank No Deer works with Tom's father but is killed by him for repeatedly stealing his money.
- The Sheriff of Piedra Town.
- A kind store owner who trades with the Indians. Jim Thatcher repeatedly stands up for Bessie's and Tom's interests.
Luther Spotted Dog
- Tom's fourteen-year-old roommate at school.
- In charge of the stables and livestock, Swanson hires Tom, only to treat him meanly when he discovers his lack of farming skills.
- The woman in charge of the girl's dormitory, Rowena also teaches English. She serves as the unofficial mother to the schoolchildren and acts kindly toward Tom.
- Ed runs the cobbler's shop at the school; he notices Tom's skill at basketmaking.
- The prostitute who approaches Tom in the street.
- A doctor who helps Tom with his arm.
- A talkative nurse in her mid-thirties. Mary takes good care of Tom in the hospital.
- A man who challenges Tom to ride a bronco in Bayfield.
- Ferguson is a doctor at the hospital who advises Tom never to ride broncos again.
- The owner of a flock of sheep at Pagosa. Jim hires Tom as a herder after his accident.
- A shepherd who also works with Jim Woodward.