Henry Mullins, a young cowboy from Southern California, sits back and watches the woman he loves marry someone else. That's when he decides to leave and ride off into the great unknown. Intending to get to Los Angeles, he is forced inland by marauding Mexican bandits and eventually into the Sierra Nevadas, where he starts to trap wild animals to stay alive. Coming across a bi-annual meeting of trappers, he begins to learn the tricks of the trade and takes up trapping seriously. Attacked by wolves, bears and the elements, Henry gradually learns the art of survival. And then he comes across a teepee with a beautiful squaw and her dying grandfather inside. Henry's life begins to change. Winter sets in high in the mountains, Henry's first. And it turns out to be the biggest battle Henry has ever faced.