Indian Springs rancher Ann Jordan writes to Washington, D.C. for help in bringing to justice the outlaws who murdered her father and are terrorizing the local ranchers, and the government sends U.S. Marshals Nevada McKenzie and Sandy Hopkins to investigate. As Sandy and Nevada near the town, rancher Ted Connors and his two brothers are nearby, rounding up their cattle. Suddenly, a band of rustlers shoot and kill Ted's brothers and leave him for dead. After the rustlers depart, Ted mounts his horse and rides to Ann's ranch. When Ann hears Ted's account of the attack, she leaves him in the care of her aunt Sally and drives her buckboard to town to summon Doc Edwards to treat the wounded man. In the town saloon, meanwhile, Matson, the covert head of the outlaws, shakes hands with Kelbro, the man he has just hired to impersonate a circuit judge. When Ann enters the saloon looking for Doc, who is passed out drunk at a table, Matson introduces her to "Judge Kelbro." After accusing Matson of hiring a phony judge, Ann loads the unconscious Doc into her wagon and speeds away just as Nevada rides into town. In the saloon, meanwhile, Matson tells Kelbro of his plans to drive the ranchers from their land and establish a new town to meet the forthcoming building of the railroad. After a confrontation in the saloon with Matson and Kelbro, Nevada rides to the Jordan ranch and is followed by Matson's thugs. At the ranch, Ann is met by Sandy, who is posing as an unemployed ranch hand. Although Ann is suspicious of Sandy, Aunt Sally welcomes him into the house. Shortly afterward, Nevada knocks at the door and is invited in by Aunt Sally. As Nevada and Sandy confer in the kitchen, Matson's thugs arrive and, spying Ted through a window, shoot and wound him again. Nevada and Sandy chase the thugs away, but lose them on the trail. Sandy then rides to town to investigate Kelbro, while Nevada returns to the ranch and, after revealing that he and Sandy are U.S. Marshals, asks Doc to spread the word that the outlaws killed Ted. In town, meanwhile, Sandy, pretending to be drunk, stumbles into the saloon and tricks Kelbro into producing forged papers regarding his judgeship. After Matson sends his gang to steal the Jordan cattle, Sandy follows. Claiming that they are a posse deputized by the judge, the outlaws capture Sandy and, after accusing him of killing the Connors brothers, decide to hang him at the site of the killings. At the Connors' camp, meanwhile, Ann and Nevada bury the two dead brothers. When they see the gang approach, they hastily erect a grave for Ted. The gang declares its intention to hang Sandy, but Nevada insists that Sandy be given a fair trial and takes him into custody. After the "posse" rides off, Sandy tells Nevada that he suspects that Kelbro's papers are forged. Nevada and Sandy then ride to town and after producing their marshals' badges, Nevada seizes Kelbro's papers and sends Sandy to the state capital to verify them. As Sandy departs to board the next stage to the capital, Ann gallops into town with the news that her cattle have been stolen. Nevada then joins Ann and the now-recovered Ted and, as they pause along the trail, they overhear Matson's gang planning to bushwack Sandy's stage and steal Kelbro's papers. After dispatching Ted and Ann to search for the rustlers' hideout, Nevada rides to the stage just in time to join Sandy and fend off the attack. When the driver is shot, Sandy takes the reigns, while Nevada rejoins Ted and Ann, who have located the hideout. After overpowering Waco, the lookout, Nevada takes him to the ranch for questioning. Instructing Ted to stand at the window, Nevada convinces Waco that he has seen a ghost and terrifies him into confessing that Matson is the mastermind behind the gang. In town, meanwhile, Bart, one of the gang who has witnessed Waco's capture, reports to Matson. When Matson orders his gang to attack the ranch, Doc overhears and rides to warn Nevada. While Ted, Aunt Sally, Doc and Nevada brace for the attack, Ann gallops to meet Sandy, who has just returned to town. Nevada and the others return the gang's gunfire, just as Ann and Sandy arrive at the ranch, and together, they capture Matson and his gang. Their mission accomplished, Sandy and Nevada congratulate Ann and Ted on their forthcoming marriage, then ride into the sunset.