In the 1870s, Sandy Poli (Vera Hruba Ralston), the daughter of a railroad magnate, marries professional gambler John Devlin (John Wayne) against her father's wishes. From Chicago, the couple head west, intending to buy land in the Dakotas that will increase in value once the railroad arrives. Along the way, they meet Jim Bender (Ward Bond), a saloon keeper who reveals his intention to force out farmers in the territories in order to claim their land. The Devlins realize they must make a stand.