In 1842, a wealthy Oregon man named Montgomery, Herbert Rudley, rules with an iron hand, enforcing a stark law: any unmarried woman must go with the man who lays claim to her. After his wife Hannah Montgomery, Yvonne De Carlo, is attacked by an unseen assailant, Montgomery points the finger at his rival, Dan Kirby John Gavin.
Dan Kirby's Indian wife, Paca, Mara Corday, pleads with Hannah to save her husband, but they are too late. Paca makes a break with Hannah to return to her people but is pursued; an Indian named Five Crows attempts to help but is murdered. Paca is captured by a white man, Sile Doty, Robert J. Wilke, who makes her his property and returns her to his house.
A stranger, Tex Kirby, Rory Calhoun, rides up to the Montgomery ranch, asking for directions to Dan Kirby's ranch. Hannah tells him, but Tex finds Kirby dead. He heads into town and asks for work at the saloon. He’s directed to Sile Doty’s ranch, where he meets his former sister-in-law Paca and reveals he is Kirby’s brother, a former Texas Ranger. She explains that she is now the property of Doty and how Kirby was killed. Tex vows revenge and waits for Montgomery to return. Tarp Penny, Neville Brand, his father Pop Penny, Emile Meyer, and the town gambler are supposed to warn Montgomery that Tex is coming for him. Indians are massing to avenge Five Crows' death, and Montgomery may be killed by them, so they head to his ranch to claim Hannah. Both argue over her, and Tex watches the scene unfold, ultimately taking Hannah away.
Doty arrives with Paca at the survey site, warning Montgomery that Tex is waiting for him. Montgomery tells Paca to talk to the chief and guarantee his freedom to return to his ranch where he will give them the man who murdered Five Crows; if she won’t help, he’ll have her killed. He plans to frame Tex instead. Paca returns to talk to the chief.
Tarp chases Hannah and wounds her, then kills the gambler and his father. Tarp ends up in a shootout with Tex that turns into a violent fistfight after both run out of ammunition. Tex prevails when Tarp is accidentally impaled on a bison head’s horns knocked off the wall.
Montgomery is intercepted by an Indian party and taken to the chief. The chief promises to allow him to return to his ranch “after the ceremony.” His body is dragged back to his ranch, and Paca—now wearing Indian garb—rides off with the tribe, having avenged her husband’s death. Tex offers Hannah a chance to join him, and she accepts, stepping toward a new path alongside Tex.
