On a cattle drive Hoppy, camp cook Windy, companion Lucky, and young Artie Peters encounter an eccentric professor. The professor professes to be searching for the evolutionary missing link, but in reality he is a cattle rustler who uses his dynamite to scatter the cattle in order capture some of them. Hoppy and Bar 20 guys ultimately capture the professor.
American federal agent Clark Stuart is on assignment in Santa Fe to draw up a trade agreement with the newly installed Mexican governor. Meanwhile, Walter Jamison leads a wagon train from Missouri, hoping to take advantage of the new agreement. Among Jamison's passenger are famed frontiersman Jim Bowie and a very youthful Kit Carson. The destinies of all these personalities intersect when villainous ex-governor DuPrey schemes to undermine the treaty and take over the New Mexico territory for his own vile purposes. Somewhere along the way, Davy Crockett joins the "good guys" in their efforts to thwart the despicable DuPrey.
Lawyer Bowdre has started a war between the ranchers and the homesteaders planning to take over the homesteaders land when they are wiped out. Rancher Dan Stockton, having just married homesteader Gail Dawson, is caught in the middle. He suspects Bowdre is behind the war and it's not long before he gets a chance to prove it.
Unable to legally capture and sell a herd of protected wild horses, corrupt rancher Rance Macgowan uses his trained killer horse, Volcano, to substitute for the real leader of the herd and cause havoc and death among the ranches. With the government about to drop the restrictions on rounding up the herd, the Three Mesquiteers find themselves in the middle of the controversy after their friend, Sheriff Miller is killed by Volcano.
Hoppy goes undercover as an outlaw (which permits him, for once, to drink and be mean to children) to track down a bunch of outlaws operating along the border. Loco, the head bad guy, deflects suspicion from himself by pretending to be a moron.
The Commandant is making life rough for the colonials in Spanish California. While trying to help, Zorro is charged with the murder of the new Governor, but in the end he triumphs over the evil Commandant.
In his film debut Ritter is sent to investigate miners being killed and their mines confiscated. The culprit is Evans and after Tex joins the gang, he is sent to kill two more miners. When Estaban is killed, Tex is put on trial for all three murders.
At the Texas Centennial in Dallas Autry confuses two girls by being himself and his own stunt double. When cowboy star Tom Ford disappears, Wilson gets his double Gene Autry to impersonate him. But Ford owes gangster Rico $10,000 and Rico arrives to collect. He fails to get the money but learns that Autry is an impersonator and now blackmails Wilson and his movie studio. Original version runs 71 minutes, edited version runs 59 minutes.
A crusading newspaper editor recruits his old friend Hoppy to take the job of Marshall in a town rife with vice and murder directed at helpless miners.
It's just after the Civil War and Captain Morgan and his confederate soldiers are establishing a town on the Bozeman trail. Colonel Strong and his union men are at the nearby fort. Things are peaceful until Riley has the Indians attack a union wagon train and leave a confederate sword at the scene.
The arrival of the telegraph put Pony Express riders like John Blair and his pal Smoky out of work. A race will decide whether they or stageline owner Drake get the government mail contract.
A lawman captures the notorious "Pecos Kid", who is tried and hanged for his crimes--then starts to have doubts as to whether the Kid actually committed the crimes.
An evil gang is involved in both cattle rustling and the robbing of stagecoaches. Hoppy must stop them without help from the sheriff who turns out be a major outlaw himself.