A mysterious rider, known as Whitehorse Cactus, steals from the dishonest water company in order to help ranchers who have been cheated out of their water rights by its crooked agents. This elusive champion is, in actuality, Jack Hayes, whose vendetta began when his father was brutally slain by one of the hired gunmen of John Henderton, the owner of the water company. Riding in the hills one day, Jack stops the runaway horse of Henderton's daughter, Belle, who was his childhood sweetheart. Jack kills one of Henderton's hired gunmen, is tried and convicted, but escapes with the help of Panhandle George. Henderton is shot, and Jack is accused of the murder. Belle captures him, only to be told by the sheriff that she has the wrong man. Belle and Jack are reconciled, and soon they get married.
—AFI Catalog