In Arizona when the rodeo is held, the boys of the Diamond S Ranch capture the majority of awards in almost all the feats of skill peculiar to the western plains. Particularly does Tom, a cowpuncher of the Diamond S Ranch, prove his skill in riding and roping, an added incentive, perhaps, being the fact that Mary Johnson is an eye-witness. Jim Owens is a rival for the love of Mary, and is also a cowpuncher without principle. He is consumed with jealousy when he sees Tom capture prize after prize, and he resolves that any means are worthy to put a stop to Tom's triumphs. He secretly severs the girth of Tom's saddle, and when the cowpuncher is performing a dare-devil feat of horsemanship, the saddle breaks and he is flung to earth and rendered unconscious. The cause of the accident is discovered and a search is made for the guilty one. Mary suspicions Jim, and Tom's accident finally causes her to make up her mind between the two men, and she promises Tom to be his wife.