While riding across Wyoming sheep grazing land, out-of-work cowhands Dave Saunders and Chito Rafferty see a group of sheepherders on horseback chasing a cowboy. Investigating, Dave comes across the sheepherders, led by Jess Rawlins, the foreman of the Big M sheep ranch, as they are about to lynch the man, Tug Caldwell, for rustling. Taking the sheepherders by surprise, Dave prevents the lynching and flees with Tug and Chito to the nearest town. There, in a "cowboys only" saloon, a grateful Tug introduces Dave and Chito to his boss, Dawson, while Chito is reunited with saloon singer Ruby, one of his many sweethearts. With guns drawn, Rawlins and his men then burst into the saloon and disarm all of the cowboys. Accusing Dawson of theft and duplicity, Rawlins is about to fire on him when Ruby slips Dave a pistol and he shoots the gun out of Rawlins' hand. After the cowboys chase off the sheepmen, Dawson hires Dave and Chito as ranch hands. Later, in the town's telegraph office, Chito discovers that Rawlins has received a message from Chris Marvin, the absentee owner of the Big M, who is on her way to Wyoming. Confident that he can clear up matters with Chris, Dawson sends Chito and Dave to meet her stagecoach. On the way, however, the cowboys notice Scotty, one of Rawlins' men, driving sheep onto Dawson's land. Realizing that Scotty is trying to frame Dawson as a rustler, Dave and Chito tie him to a tree, then drive the sheep back toward the Big M. Rawlins, meanwhile, intercepts the stage outside of town and informs Chris of Dawson's "duplicity." As Chris and Rawlins ride to the Big M, they see Dave and Chito herding their sheep. Rawlins and his men pursue Dave and Chito, who ride to retrieve Scotty, whom they believe will prove their innocence to Chris. Rawlins stumbles upon Scotty before the cowboys do, however, and shoots him in cold blood, then claims that Dave and Chito did the deed. Although Rawlins tries to have the cowboys lynched, Chris insists that they receive a fair trial and sends for the marshal. After Chris imprisons Dave and Chito in her bunkhouse, Ruby hides a gun in Chito's guitar, then gives him the instrument with Chris's permission. Chito and Dave escape and, with Dawson, head for the local undertaker, where they hope to obtain proof that the bullet that killed Scotty did not come from their guns. The undertaker reveals that the fatal bullet came from a rifle, a type of gun that neither Dave nor Chito own, but as the undertaker is assuring the cowboys that he will testify on their behalf, Rawlins shoots him through an open window and flees. With no witnesses, Dave and Chito decide to confront Rawlins at the Big M. Before they reach the ranch, however, they meet up with Chris, who upon hearing about the undertaker, agrees to question her foreman herself. Chris, Dave and Chito surprise Rawlins as he is about to abscond with Chris's money, but while Chito is holding him prisoner, Rawlins manages to escape once again. Dave, meanwhile, demonstrates to Chris that Rawlins' rifle fired the bullet that killed Scotty. Finally convinced of the cowboy's innocence, Chris leads them to a place near the Colorado border where she had earlier discovered some mysterious sheep hoof marks. Chito then remembers that Rawlins had sent a telegram to a man in Colorado, and Chris deduces that her foreman has been herding her sheep across the Colorado border and selling them. At the border, Chito, Dave, Dawson and Chris engage in a gunfight with Rawlins and his men. After the sheepmen surrender, Dave knocks Rawlins unconscious with one punch. With peace restored, Ruby then proposes to Chito, who flees in a panic from his would-be bride.