South Texas wrangler Tom Kilpatrick buys a ranch in the Pecos country, where he hopes to settle and introduce progressive ideas about ranching. Allied with Tom in his effort to improve ranching in the region is John Rambeau, a friend of Tom's father, who helps him persuade other ranchers to pool their money and invest in a Brahma bull. The bull, Tom argues, will help improve the quality of the cattle population, which, in turn, will make all the ranchers more prosperous. The ranchers approve Tom's plan, and soon the bull, named Shannagon, is delivered to John's ranch. However, due to the carelessness of Windy Lucas, a peddler, Shannagon escapes into the hills. Windy remains silent about his role in the escape, but, unknown to him, the mishap was witnessed by Larch Keegan, a young man who is in love with Windy's adopted daughter Cherry. Hoping to win Cherry from Tom, who is also in love with Cherry, Larch places the blame for Shannagon's escape on the south Texan. Larch and his two brothers, Hoy and Happy, spread false rumors about Tom and soon have the entire valley turned against him. Cherry overhears Windy and Larch discussing the plot, but, out of loyalty to her foster father, keeps the truth a secret. Shannagon, meanwhile, roams the countryside, destroying property and injuring people and other animals. Although the Keegan brothers make known their readiness to shoot the bull when they find it, Tom persuades them to let him capture it instead. Tom eventually finds Shannagon, but the bull escapes back into the hills. Realizing that his only hope of capturing the bull is with the help of a strong wild horse known as Widow Maker, Tom sets out in search of the horse. Brimming with jealousy over Tom's romantic pursuit of Cherry, Larch vows to burn down the Texan's ranch house. Cherry, however, discovers Larch's plans, and decides to prevent him from carrying them out by marrying Tom. The marriage plans go awry, though, when Windy inadvertently tells Tom the real reason Cherry wanted to marry him. Out in the wilderness, Tom finally captures Widow Maker, but Larch follows the wrangler and releases the horse. Tom and Larch then settle their differences in a bruising fistfight, and Larch is given a severe beating. Tom gets another chance to capture Shannagon when the horse returns to him, and this time he is successful. Having beaten Larch and the Keegans conclusively, Tom turns his attention to Cherry, who is now ready to marry him for the right reasons.