In the cañon country of southern Utah, Jane Withersteen, a Mormon-born spinster, has inherited a valuable ranch and spring which is coveted by other Mormons in the community. When Jane refuses to marry one of the Mormon elders and instead befriends Venters, a young Gentile rider, the Mormons begin to persecute her openly. Meanwhile, Lassiter, a notorious gunman, arrives at the Withersteen ranch in search of the grave of his long-lost sister, and stays on as Jane's defender while Venters is on the trail of a gang of rustlers that includes a mysterious Masked Rider.