In the Utah Territory, in 1881, renowned gunslinger John McKay "Ringo" Baker, who is wanted for the murder of an Army captain, outsmarts some pursuing cavalry troops and eludes capture. When Colonel Price, the troop leader, learns that Ringo is heading north, he sends Lieutenant Mike Baker, Ringo's younger brother, to capture him. In a remote canyon, Mike tracks down his brother, who grazes him with a bullet, apologizes, and then escapes again. Sometime later, on the trail, an unarmed Ringo meets small-time rancher Glenn Larrabee and his hand, Stuart. The three men then witness elderly Sam Jeffries being chased in his wagon by thugs Dancer, Fergus and Polk, and ride to help. The thugs are soon joined by their boss, Wade Proctor, the owner of the large Bar K ranch, and Judge Thomas H. Cole, who accuse Sam of trespassing on a road Proctor claims is legally his. After Glenn protests Proctor's greedy ways and is knocked down by Fergus, Ringo, who introduces himself as Steve McKay, takes on Fergus and knocks him out. Impressed, Proctor offers Ringo a job, but Ringo declines. Glenn also tries to interest Ringo in a job, explaining that Proctor has been intimidating the smaller ranchers into selling their herds for next to nothing. Once again Ringo refuses the offer, then rides to the nearby town of Gunlock to reunite with Livvy Weston, his former sweetheart. After assuring Livvy, a widow who owns a restaurant in town, that he shot the Army captain in self-defense, Ringo asks her to run away to Canada with him, but she turns him down, admitting that she has a new beau. When Ringo discovers that Proctor is her beau, he changes his mind about leaving and becomes Glenn's partner. At a goodbye party for Sam, who feels he is too old to fight Proctor, Ringo dances with Livvy, arousing Proctor's jealousy. Proctor then accuses Sam, who has sold his herd to Ringo and Glenn for a higher price than Proctor had offered, of double-crossing him, and the fast-shooting Dancer challenges Glenn to a gunfight. Before either one can draw, however, Buck Yallup, a traveling gunsmith, pulls up and interrupts the fight. Ringo then suggests to the smaller ranchers that they pool their herds to protect themselves against Proctor's harassment. Proctor later justifies his actions to Livvy by insisting that he is acting within the law, which grants him priority rights for being the first to graze his cattle on unclaimed range land. To solidify his legal position, Proctor pressures the weak-willed Judge Cole into posting notices declaring most of the open range land in the area as Bar K property. Soon after, Dancer, Fergus and Polk ride up to Glenn's roundup camp, and while Dancer provokes Stuart into a gunfight, which Stuart loses, Fergus and Polk cause Glenn's herd to stampede. Furious, Glenn confronts Judge Cole, whose daughter Louise is Glenn's fiancée, and accuses him of caving in to Proctor and indirectly causing Stuart's death. Although Louise defends her father, Judge Cole realizes he has been a coward and decides to cancel the notice. As the judge and Louise are posting the cancellation, Proctor's henchmen attack them, and Proctor proclaims that the original notice is still legal. Despite the intimidation, Judge Cole remains committed to stopping Proctor and asks Ringo to organize a ranchers' meeting. As Ringo is riding into Gunlock with Glenn, however, Livvy informs him that the cavalry are in town. Before Ringo slips away, he is spotted by Mike, who agrees to give his brother a modest head start. Proctor happens to overhear Mike call Ringo by his real name and orders his men to intercept the fugitive. Aware that Glenn and Judge Cole are talking with Colonel Price about the range war, Proctor shows up with a captured Ringo and accuses him of causing the unrest among the ranchers. Colonel Price believes Proctor's story and orders Ringo and his troops out of town. As soon as the soldiers depart, Dancer challenges a drunken Glenn, who has vowed to continue fighting Proctor, to a gunfight. Although Proctor protests to Livvy that there is nothing he can do to prevent the showdown, she and Louise take matters into their own hands and stop the fight at gunpoint. Livvy then realizes Proctor's true nature and denounces him as a murderer. Stunned by Livvy's rejection, Proctor angrily orders his men to attack the jailhouse where Glenn has been taken. Before the order is carried out, Louise rides to alert the ranchers, who race to town together. A fierce gun battle ensues, and just as Proctor's men are about to storm the jail, Ringo, having escaped from the cavalry, appears. Using a gun supplied by Buck, Ringo outdraws both Dancer and Fergus, and Proctor collapses in the street from a gunshot wound sustained during the battle. Later, Colonel Price returns to Gunlock to recapture Ringo, who gives himself up willingly, buoyed by Livvy's devotion.
