In 1878 Kansas, cattle buyers find their supply of trail herds gradually depleted. Rancher Gene Autry purchases one of the last herds to arrive, and learns from cattleman Uncle John Copeland that the Texas cattle trails have been blocked by homesteaders stringing barbed wire across their territories. When Mayor Bill Whitson asks Gene if he will open the cattle trail, Uncle John suggests that Gene begin his undertaking in Osborne, Texas, a near ghost town due to the poverty of the cattlemen and homesteaders alike. In Osborne, Gene discovers his old friend "Buckeye" Buttram, a government land agent. Shortly after Buckeye closes a deal with newcomer August Gormley, two cattlemen attack his office and are seen by Gene and newspaper publisher Gay Kendall. Gay notices the attackers' horses bear the brand of Diamond Head ranch. After Gene halts the attack, he and Buckeye discover a threatening note demanding that no further land be sold. Wealthy Steve Ruttledge, owner of Diamond Head and a former military officer who lost one arm during the war, rides into town concerned over Gay's safety and assures Gene he wants no difficulties with the new homesteaders. Gene decides to meet with the homesteaders to try and convince them to open up their land. At the McGraw place, Gene and Buckeye discover only a shelter, not a house, and are angrily forced off the property by McGraw. At Ed Parker's place, Gene also notices only a tiny shack on the premises, and when Buckeye asks to inspect the building, Parker starts a fistfight rather than allow the investigation. Gene asserts that the phony homesteads are an obvious obstruction against the cattle drives. When Buckeye tries to take Parker in to the marshal for assaulting a government agent, Parker escapes. Parker then reports to Ruttledge, who reassures him that he will protect all of the bogus homesteaders that he has hired, because he intends to force public demand for a railroad, which will then have to purchase his land. Ruttledge further observes that the genuine homesteaders, most of whom are starving and struggling, will also be dependent on him for their supplies. Later, after Uncle John and several cattlemen discover that August has killed a stray cow for food, they accuse him of rustling and throw him off his land. A few days later Gay's newspaper announces that Uncle John has been found dead. Uncle John's death notice has been planted by Gene in an effort to gather the cattlemen in one place, and during the funeral services, the cattlemen are startled to hear the "ghost" of Uncle John pleading for them to put a stop to the phony homesteaders and discover a way to continue their cattle drives north. When Gay demands to know the truth about Uncle John's "death," Uncle John reveals himself and several cattlemen agree to contribute to a vast herd and a new drive. Suddenly, Uncle John is shot through an open window, and when several men run outside and see August hastening away, Ruttledge shoots him. Back inside, Gene tells Buckeye he is sure his shot winged the assailant, and they then notice one of Ruttledge's henchmen with a grazed hand. In honor of Uncle John, the cattlemen adhere to their promise and put together an enormous herd to drive to Kansas. At Gene's request, Buckeye spies on the goings on at Diamond Head, but is captured by Ruttledge's men. Gene comes to Buckeye's rescue and after a fight with Ruttledge's gang, discovers Ruttledge's railroad plans. Gene instructs Buckeye to bring the cattlemen to the heart of the phony homesteads to clear the trail for the drive. Ruttledge and his men chase Gene and the cattlemen, but Gene is able to destroy a sizeable portion of the barbed fences before having Ruttledge and his gang surrounded and captured. With the trail now open, the cattle drive continues north to Kansas.
