The official Mountain Dog book trailer by Margarita Engle. When Tony's mother is sent to jail, he is sent to stay with a great uncle he has never met in Sierra Nevada. It is a daunting move—Tony's new world bears no semblance to his previous one. But slowly, against a remote and remarkable backdrop, the scars from Tony's troubled past begin to heal. With his Tió and a search-and-rescue dog named Gabe by his side, he learns how to track wild animals, is welcomed to the Cowboy Church, and ma