Beyond the Last Frontier was the first entry in Republic's "John Paul Revere" western series. Journeyman actor Eddie Dew stars as Revere, a Texas Ranger who goes undercover to smash an outlaw gang. Meanwhile, the villains install an informer amongst the Rangers, meaning that Revere will have to take care of this guy before he can complete his assignment. While Eddie Dew was OK in the lead, his thunder was stolen by the young actor cast as "Trigger Dolan"-future superstar Robert Mitchum. The plot was a bit too complicated for a film of this nature, thus future John Paul Revere installments were a bit easier to follow.

Dan Hurley wants to sell wild horses and is trying to get the Wild Game Laws that protect them changed. To get his petition signed, his henchman paints his trained horse to look like the wild horse leader and has it kill a man. Johnny Revere finds traces of paint on a horse and tries to arrest Hurley and his men. But he is captured by the gang and is now slated to be the next victim of the trained horse.

To combat the lawlessness in her town, school teacher Carrie Stokes writes to her former students in search of a lawman. Johnny Revere arrives and starts to clean up the town. But things go bad when he is hit on the head and loses his memory.