Cholita, after a long absence in Mexico City, is returning home to take up her duties as head of the rancho and, as everyone expects, to marry her childhood sweetheart José. Expectations are somewhat dashed as she shows up with Fernando to whom she is engaged. This makes José and Cholita's uncle more than a little bit put out as Fernando is not only not a Mexican, he is also a city slicker afraid of the country.
To fight a poisonous weed, ranchers are burning their land. Gene is the Inspector brought in and he recommends spraying. The spraying goes well until the Larabee ranch is reached. When Larrabee refuses to allow the equipment on his land, Gene has it sprayed by airplane. Cattle must stay off recently sprayed land and when a Larrabee man shoots down the plane, the crash sends the cattle stampeding toward the newly sprayed land.
Billy the Kid and his pal Jeff help their friend Fuzzy Jones escape from jail, and the trio heads for Paradise Valley, where they find the Paradise Land Development Company, ran by Matt Brawley and Jack Saunders, is somewhat less than honest in their dealings with the homesteaders. They devise a plan to cause a split between Brawley and Saunders.
The Rough Riders are after a gang of rustlers. Marshal Roberts is posing as a wanted outlaw, McCall is the Marshal supposedly after him, and Sandy is on hand as a cook. Roberts hopes his joining the gang will help bring them in.
Rodeo champ Gene Autry inherits half interest in both a ranch and a mine that provides steady employment for the surrounding rancheros. Unfortunately, the other half goes to Easterner Barbara Erwin (Carol Hughes), who is only interested in monetary remuneration. To convince Gene to buy her share, Barbara enters into an unholy alliance with unscrupulous attorneys Arnold (Ivan Miller) and Fry (Sam Flint), who, without their client's consent, hire a gang of thugs headed by Tommick (John Merton). When a ranchero (Elias Gamboa) is mortally wounded in the ensuing gun battle, Barbara sees the error of her way and switches sides.
Gene returns from the East with new ranch owner Tom Bennett to find everyone's cattle dying. Blaine has reopened the copper mine and the waste is poisoning the water supply. While Gene is away Tom confronts the miners and a man is killed in the ensuing gunfight. Now Gene not only has the dying cattle problem but his ranch owner is in jail.
When the showboat hits town, two men use the parade as a distraction to rob the bank. Their accomplice is Pop, the clown from the showboat. He leaves the money on the boat and tells his daughter Patsy to bring it to him at a later stop on the river. Gene's investigation of a bank robbery takes him to the showboat where he becomes a performer. Gene and Frog try to find the money while helping Patsy and her father.
Williams is out to stop Ellen Goreham from completing her road that is under construction and is using a man to impersonate Billy the Kid. When Billy sees the wanted posters and learns of the murders he supposedly committed, he sets out to find the imposter. His sidekick Fuzzy is there to help him but his friend Jeff, now a Marshal, is also after him.
Stephen Westcott and Ed Martin scheme to put Jane Travers' wagon line out of business. They want to use it take over all the wagon- train traffic going west. Hoppy, California and Lucky must make sure that doesn't happen.
As a penalty for fighting fellow classmates days before graduating from West Point, J.E.B. Stuart, George Armstrong Custer and four friends are assigned to the 2nd Cavalry, stationed at Fort Leavenworth. While there they aid in the capture and execution of the abolitionist, John Brown following the Battle of Harper's Ferry.
Bill Hickok, assisted by Calamity Jane, is after a foreign agent and his guerrilla band who are trying to take over some western territory just as the Civil War is coming to a close.
Drifter Cole Harden is accused of stealing a horse and faces hanging by self-appointed Judge Roy Bean, but Harden manages to talk his way out of it by claiming to be a friend of stage star Lillie Langtry, with whom the judge is obsessed, even though he has never met her. Tensions rise when Harden comes to the defense of a group of struggling homesteaders who Judge Bean is trying to drive away.
Trouble in Colorado is tying up Union troops needed back east during the Civil War and Lieut. Burke is sent to investigate. Macklin and his gang are causing the problems and Capt. Mason joins them. When Burke catches up with them he also finds Mason, his brother.
While Sam Houston in in the nation's capital trying to get Texas into the Union, his aide is trying to impose a self-serving tax on the use of the Santa Fe trail. The lady owner of a wagon train is using the trail, and a Texas Ranger comes to her assistance.
Easterner Madeline Hammond buys a ranch not knowing Hayworth is using it to smuggle ammunition across the border. When trouble starts, she brings back Gene Stewart ex-foreman who left the country after fighting with the Sheriff.