Cowboy Jack Carter, the proud owner of the Australian shepherd Bunk, accepts the challenge of corralling 10,000 wild horses within a 10-day period. With the enormous sum for his efforts, Jack prepares to propose to Jessie Hayden. Unfortunately, Jack finds out, that his rival Charlie Champion has beaten him to it. Charlie dispatched by the wild horse Stampede however.
WITH HIS WONDER-HORSE "SCOUT" AND HIS DOG PAL "REX" (original poster-all caps)