Lucky Larkin.

Colonel Lee, a homesteader, is the object of terrorists who want to drive him off the range so that his horses cannot be entered in the county races, and he refuses an offer of Martin Brierson to buy him out. Pete, Brierson's brother, in hiding because of his criminal record, burns the colonel's barn and injures his horses. Convinced of Brierson's responsibility for the terror tactics, "Lucky" Larkin plans to ride Tarzan, the colonel's pet colt. Brierson does his best to disqualify the horse, but Larkin tricks him and wins the race. Larkin captures Pete and forces him to confess. The Brierson brothers are brought to justice, and Larkin wins Emmy Lou, a homesteader's daughter.