When part of Indian Territory is incorporated into the United States, good-natured rancher Vance Cordell reluctantly accepts the badge of federal marshal when a flood of notorious outlaws views the new area as ripe for banditry. Included are the Dalton and Younger Gangs, Billy the Kid, and the Sundance Kid led by the notorious Wild Bill Doolin. Cordell has a personal stake in his campaign to eradicate the bad men because of a friend's murder and the robbery of the local bank owned by his future father-in-law.