Rancher Cal Pierson (James Marcus) becomes paralyzed and his foreman Ranse Willard (Ward Bond) takes charge. Keeping Cal and his nurse Alice (Geneva Mitchell) prisoners in the ranch house, Ranse builds a barbed-wire fence across the narrow entrance to the valley and demands five dollars a head from every cattleman who drives his herd through the pass. Cattleman's Association investigator Ken Martin (Ken Maynard), posing as a slow-talking and slower-thinking itinerant peddler, sizes up the situation when he rides up onto a fight between Ranses's henchmen and cattle Chet Rogers (Edward Hearn) and Bob Buckner (Dick Rush.) Ken, disguised as the old peddler, saves Chet's Life, and consents to carry a message to old Cal asking if he really wants the pass closed. Ken, now disguised as a masked rider, is chased by Ranse's men, but changes back to the peddler, and tells the pursuers he can identify the masked rider. Ken tells Ranse he knows the rider is going to tear down the fence that night. Ranse and his gunmen leaver for the pass, where Dolson (Sheldon Lewis) tells Ranse that the cattleman intend to stampede their cattle through the pass. Ranse decides to let the herds pass through, ambush the ranchers and take the cattle. But Ken and his horse Tarzan are on the way.