The Promise: A Wyoming Story by Jim Watt

Taylor Robin Morrissey, at fourteen years of age, has his safe New Jersey middle class home broken up when his father goes to prison and his mother drifts into alcoholism. His only relative is his grandfather who is a small rancher in Wyoming, but who is estranged from Taylor's family. He decides to hitchhike to his grandfather to try to put a family back together again. On the way he has one adventure after another and eventually learns that his family has a significant role in the history of the West and he has inherited an obligation to continue it.