Vaughn Monroe

Rhiannon, an outlaw who regularly robs gold from the stagecoach, shoots the new sheriff and then carries him to the doctor. The doctor cleans up Rhiannon and presents him to the sheriff as the man who saved his life. Rhiannon is deputized by the sheriff, and becomes torn between his new life and the prospect of robbing the next gold shipment. (imdb)

In Arizona, Marshal Landry and captured outlaw Girard find three survivors of a wagon train massacre but, later, Girard escapes custody and robs stagecoaches with his gang, prompting Landry and his posse to give chase.