Two young horse traders guide a Mormon wagon train to the San Juan Valley and encounter rugged terrain, the cutthroat Clegg gang, hospitable Navajo, and moral challenges on the journey.

Hoppy is busy chasing stagecoach bandits who sing as they rob.

Lee Garvin has eloped with the daughter of a railroad man who didn't approve of the marriage. Hoppy steps in when the young man is framed for murder.

A banker is trying to cheat people out of their silver-rich land. Hoppy learns that the banker is in league with an outlaw gang.

At the reading of his late cousin's will, California learns the estate will be divied among whoever remains of the seven relatives. With one already dead, another immediately murdered, and the Lawyer telling them the ranch is almost worthless, Hoppy investigates.

Belle Langtry runs a town being taken over by cattle rustlers. She is also a front for the outlaws, who are led by Steve Fraser. Hoppy gets elected sheriff and cleans up the town with help from the Bar 20 boys.

Hoppy and new sidekick California Carlson head to California to help out Lucky Jenkins.

Buck Peters arranges for Hoppy, California, Johnny and other cowboys to go to the aid of friends whose cattle are being rustled. Hoppy and California locate the rustlers' hideout and join the gang by posing as outlaws themselves, but must find a way to let the rest of the posse know where they are.

Hoppy, California and Lucky arrive at a remote inn, where Lucky expects to be married - but finds the bride-to-be in distress over her uncle, who has suddenly disappeared from the inn. Then Hoppy finds the uncle's body in the shaft of his nearby mine...

Hoppy, California and Johnny partner up with brother and sister ranch owners, two of several who are having their access to water blocked by a dam owned by a greedy merchant in town, who is intent on driving them out and taking their land for himself.

One of Hoppy's Bar 20 ranch hands is tricked into participating in nefarious activities after being subjected to hypnosis.

Posing as a cattle buyer, Hoppy crosses over into Oklahoma where the Jordan brother's and their outlaw gang operate outside the law. After receiving an unfriendly reception when he finds them, he, California, and Johnny rustle their cattle and drive across the river into Texas. He hopes they will cross over to retrieve their cattle and then he can arrest them.