A Western adventure about a tough marshal's efforts to clean up a frontier town filled with brawling cattlemen, crooked officials and various bad guys out to discredit him.

Dave Harmon (Clint Walker), a former lieutenant in the U.S. Army is sent to Yuma as the new United States Marshal. His wife was raped and son killed and the only description of the criminals responsible was they were wearing army uniforms. He served in several locations as a sheriff and all were near an army post.

Harmon becomes Marshal of Yuma, a city with an army post and an Indian reservation near by. Marshal Harmon comes into town and two drunk rebel rousers, the King brothers are causing trouble. One is immediately killed by the new town marshal and the other locked up in the town jail. The second brother is murdered by one of the King brothers' cattle hands in an effort to get the third King brother to kill the Marshal. The murderer tricked an army Captain to coming with him to the jail. The plot thickens with corruption and intrigue.