The Three Mesquiteers, Stony Brooke, Tucson Smith and Lullaby Joslin, have tired of defending Tim Clay, Jr., a good-hearted but mischievous young cowboy. After helping him in his latest fight, they chastise him and declare their happiness that Tim's mother Minerva "Nervy" Clay, a local rancher, has given him her other ranch in Santa Fe as a birthday present. Tim, however, informs them that Nervy has decided he is too immature to handle the ranch, even though he has become engaged to Claire Robbins. At Nervy's nearby ranch, three men harass her and though Tim tries to defend her, only the Mesquiteers can capture them. The Mesquiteers, however, tell Nervy that Tim handled the men by himself, knowing she will award him with the Santa Fe ranch, which she soon does. A few weeks later, after Tim has left for Santa Fe, Nervy surprises the Mesquiteers by asking them to bring Tim a herd of cattle. The Mesquiteers agree, and when theys reach the Clay ranch watering hole, they find that Billy Dawson, Wid Lighton and Tom Howard are illegally charging visitors a fee to water their herds. The angry Mesquiteers suspect Tim is behind the scheme and start a fight, but when Tim and Claire arrive, Tim helps the Mesquiteers defeat the thugs and reveals that he had no knowledge of the water fee. Later, Dawson and Leighton visit their boss, the crooked judge Neil Morgan, to inform him that Tim has come to take control of his mother's ranch. After Morgan reminds them that, according to the new squatters' rights law, if they live on the range for two more weeks they will have a legal right to the land, they assume they can easily convince Tim to allow the men to stay. When Tim, however, confounds them by refusing to let them stay, Dawson and Leighton attack him, and Claire, fearing they will kill her fiancé, shoots Leighton. Dawson pronounces the man dead and convinces Tim that Claire will be jailed for murder unless he allows Dawson to stay at the watering hole in exchange for his silence. After Dawson carries Leighton from the office, Leighton sits up, unharmed. Dawson brings Leighton and Howard to an abandoned mine for the required week, then returns to the watering hole. Meanwhile, the Mesquiteers prepare to leave town, but when they see Dawson still charging a rancher at the watering hole, they run him out and return the money to the rancher. Back at Tim's house, Tim criticizes their actions just as the sheriff arrives and arrests the Mesquiteers for stealing Dawson's money. On the way to the jail, they escape but are promptly captured by Leighton and Howard at their nearby hiding place. When Leighton leaves, the Mesquiteers trick Howard and escape. They go to Morgan's, where they hear the judge tell Leighton that Dawson needs only one more day to gain ownership of the Clay ranch. Tucson and Stony chase down Nervy and Claire, who are on a stage to the next town, and inform them about the squatters' rights issue, while Lullaby chases after Leighton. Tucson, Stony and the women return to kick Dawson out, but Howard has blocked the road, forcing the Mesquiteers to battle the barricaders. As the fight rages, Tim finds his mother and confesses the truth about Leighton's death. Just then, however, Leighton rides by, and Tim captures him before joining the Mesquiteers. Together, the group defeats Howard's men and brings the villains to justice. A few days later, after Tim and Claire have married and Nervy has decided to stay on at the Clay ranch, the Mesquiteers leave, satisfied that order has been restored.