Tom Dunson is a cattle rancher who befriends 13-year-old Matt Garth when he is orphaned by an Indian massacre. Soon after, Dunson claims a piece of land for his cattle ranch with Matt and his longtime partner Horace Groot. Years later, Matt returns home from the Civil War to find that his guardian is economically broke and desperate to sell his now huge herd at a distant market. Dunson and Matt round up a motley bunch of cowboys to make the trek. But exhaustion, heat, rain, bandits, and the group's moral decay pose deadly dangers.