When the ancient continent of Mu sank beneath the ocean, some of its inhabitant survived in caverns beneath the sea. Cowboy singer Gene Autry stumbles upon the civilization, now buried beneath his own Radio Ranch. The Muranians have developed technology and weaponry such as television and ray guns. Their rich supply of radium draws unscrupulous speculators from the surface. The peaceful civilization of the Muranians is corrupted by the greed from above, and it becomes Autry's task to prevent all-out war, ideally without disrupting his regular radio show.

The adventures of a one-armed gunfighter (he lost the use of an arm during the Civil War) in the Old West.

In this Western, comprised of 12 chapters from a serial, Kit leads a group carrying a large gold shipment across the wild West. When the Mystery Riders attack and steal the gold, Kit is the only survivor. He later joins forces with the cavalry to retrieve it.

The Cisco Kid and his English-mangling sidekick Pancho travel the old west in the grand tradition of the Lone Ranger, righting wrongs and fighting injustice wherever they find it.

Cowboys and a businessman compete to find lost treasure.  

The exploits of Champion, a wild stallion who befriends twelve year-old Ricky North in the American Southwest in the 1880's. Although Ricky, who lived on his Uncle Sandy's ranch, had a magnetic attraction for trouble, he was always rescued by the Wonder Horse, aided by the boy's other bosom companion, German shepherd dog, Rebel.

The adventures of a small town doctor working in the Arizona territory during the early 1900s.

A 12 episode serial starring Rex, the King of the Wild Horses and Rin-Tin-Tin, Jr. Rex is brought from the island of Sujan, where he is worshiped as a God-Horse, to the U.S. to be trained as a polo pony. He escapes, meets Rinty and with the help of Frank Bradley is returned to Sujan. The natives have been persuaded to turn against their God-Horse, however he is rescued just in time before he is burned as a sacrifice.