Hoppy and Red are asked to investigate missing shipments of Army rifles. Their efforts to find the guns before they reach the hands of Mexican revolutionaries are hampered by a sharp-shooting lady marshal.

When a young Mexican is framed for murder, Hoppy and Red hide him from a lynch mob and attempt to trap the real killer.

Hoppy tries to help a reformed criminal, the fiancée of a wealthy rancher's daughter, when his former associates try to blackmail him into robbing the Cattlemen Association's safe.

Hoppy and Red combat a rancher and a crooked lawyer who are trying to drive immigrant settlers off their land.

Hoppy saves an innocent man from hanging and tracks down a murderer who's manipulating the feud between two rival ranchers over water rights.

Hoppy tries to prove that a traveling preacher is behind a series of robberies by three men who have a habit of vanishing into thin air.

Hoppy uses an incriminating letter and a crooked card deck to hunt down the murderers of a small boy's parents.

Hoppy's efforts to save a young woman's mine from swindlers are complicated when Red Connors develops amnesia and claims to be a Spanish nobleman.

Hoppy uses an intricately carved bracelet to trap some swindlers who are trying to cheat the Indians out of their oil-rich reservation lands.

A blind Mexican woman asks Hoppy to help her fugitive son, who's been falsely accused of murder.

When Red Connors buys some arid land on the strength of a promised irrigation project, Hoppy investigates and learns that the promoters of the scheme are guilty of forgery, embezzlement and murder.

The U.S. Army asks Hoppy to investigate when a herd of horses desperately needed for the Spanish-American War is stolen from the ranch who was supposed to supply the herd. The ranch workers insist the horses were rustled by Mexican bandits, but the Mexican authorities claim that no herd of horses crossed the U.S.-Mexican border, legal or illegal.

Hoppy and Red try to settle a dispute between Twin Rivers cattle ranchers and sheep grazers.

Hoppy helps a young man and woman who are framed as counterfeiters just before they are to claim their uncle's estate.