Some years ago, a young Ute Indian boy (Tillman Box) lost his parents but was determined to stay out in the wilds of the forests to live off the land with his best friend, the bear he called brother. But the world did not work like that anymore, and he was fetched by one of the tribal elders to be taken for schooling - at this point the boy could speak no English - much to his disgust. He was not even allowed to offer a place in his dormitory room to the bear, and soon when it became clear he would make no progress until the animal was returned to the wild, the boy was taken to a remote part of the forest and ordered to get rid of the beast. It was something he would never forget...
And then the little Indian boy grew up to be a white man in brown makeup by the name of Tom Black Bull, played by Frederic Forrest receiving an "introducing" credit. It was regrettable the producers did not put their faith in an actual native actor to essay the role, something akin to having Forrest black up to take the lead as Kunta Kinte in Roots of you thought about it, but for some reason it's more acceptable for a white actor to take on an American Indian character: Johnny Depp was at it as late as the remake of The Lone Ranger, though at least he claimed some ancestry as an excuse. Whatever, it did rather undercut the drama of this adaptation of Hal Borland's well-regarded novel.
If you could put that to the back of your mind, and though Forrest never became a megastar he did headline a fair few movies and was a recognisable face in supporting roles, then his performance was fine, nothing stellar but he didn't embarrass himself as a typically stoic idea of how an Indian should behave. However, the actor to watch was the man who played Red, Richard Widmark, who was seizing a late in life opportunity of a truly relishable role with both hands and making the most of it; Red is the ranch owner who sees Tom's potential as a rodeo rider and buys his permission to leave the reservation, effectively "owning" the young man until he is twenty-one years of age.