In 1865 while riding through Colorado, former Union soldier Ned Bannon is bushwhacked by the leader of a gang of cattle rustlers and left for dead. When he regains consciousness, Ned discovers that he is in the care of an attractive widow, Ellen, and her young son Will, members of a wagon train heading for California. Ned becomes suspicious of the train’s guides, Mort Harper and his partner Purcell, when he realizes that they are leading the train on a dead-end route that ends at Bishop’s Valley, which is owned by Ned’s half-brother, Hardy Bishop, with whom Ned hopes to reconcile. Hardy and Ned became estranged after Hardy accused Ned of causing his son Billy’s death during the recently concluded Civil War. Meanwhile, Hardy has been alerted that the wagon train is approaching, led by a man in a Union soldier’s uniform, and assumes that he is Ned. Hardy has been unable to forgive Ned for being involved in the capture of his son, who was with Quantrill’s Raiders and was subsequently executed. After the wagon train sets up camp in one of Hardy’s outlying meadows, Ned becomes even more concerned because he knows that Hardy is likely to kill anyone attempting to cross his land. As Ellen and Ned get to know each other, she tells him that after her husband was killed in the war, she decided to start a new life in the West. Ned’s suspicions are confirmed when Harper tries to convince the settlers not to proceed, but remain where they are and build homes, arguing that the land is government territory open to homesteaders. Ned then tries to warn the members of the wagon train that they may all be killed, but is ordered to leave at gunpoint by Purcell. Ned rides on to Hardy’s ranch to attempt to persuade him not to harm the settlers and, after beating Hardy in a fistfight, forces him to listen to his explanation about Billy. Hardy’s foreman, Stark, is sympathetic to Ned and tells Hardy that Billy was a reprobate and that Ned acted correctly. The next day, Hardy tells Ned that he is willing to forget their dispute over Billy, but states that he plans to drive off the wagon train. Ned persuades Hardy to give him a few days to find out what Harper is up to and heads back to the camp. Meanwhile, Zarata, the Mexican, renegade rustler who shot Ned, meets with Harper who agrees to give Zarata and his gang cattle in exchange for their help in taking over Hardy’s land. After Ned rides to the camp with three of Hardy’s men, he asks the homesteaders to leave peacefully and offers them provisions and help to reach the Humboldt trail to California, warning them that, unless they leave peacefully, Hardy will send twenty of his men to evict them. Harper claims that Ned is lying and provokes Red, one of Hardy's men, into a gunfight during which Red accidentally kills the wife of one of the settlers. Ned and the others leave but that night, Ned returns to take Ellen and Will back to the safety of the ranch. When Ned tells Hardy that he is willing to stand with the settlers, Hardy gives him more time to try to peacefully resolve the situation. Later, Ellen tells Ned about her disreputable past as a dance hall girl, and after admitting that she was never married to Will's father, states that she wants her son to have a promising future. In an attack on the ranch house, Harper, Zarata, Purcell and some of the settlers kill several of Hardy’s men. Although Hardy is mortally wounded by Zarata, he manages to strangle Zarata to death. Taking Ellen and Will hostage, Harper forces Ned to drop his gun and orders him to bring him a horse. Sensing that Harper may be out of bullets, Ned bluffs him and, recovering his own firearm, shoots him. Later, Ned checks with the new leaders of the settlers, Cap and Adam Judson, who apologize for not heeding his advice and tell him that they are moving on to California. Ned then invites them all to remain in the valley, as he has inherited the land. After Ned learns that Ellen and Will have already started north in their wagon, he rides out after them.