The Three Mesquiteers are forced to track down a train robbery ring after some of the gang hijack their truck for a getaway and the police conclude they are part of the gang, an identification which is just fine with the gang's nameless chief.

Outlaws of Sonora is a 1938 American Western "Three Mesquiteers" B-movie directed by George Sherman.

In the 18th entry of Monogram's 24 "Range Buster" films, the bank of Gila Springs is robbed by Ace Alton and his gang, and Sheriff Frank Hammond, son of Marshal Jim Hammond, is killed. The Marshal sends for the Range Busters, Dusty King, Davy Sharpe and Alibi Terhune, to come and restore order to the town. Ed Cole, head of the local vigilantes, and secretly the head of the outlaws, promptly orders the trio out of town. They visit an old friend, Rancher Mike Rand and his daughter Mary. Mary's brother Jeff has unwittingly become a gang member, and carries out Cole's orders by taking a shot at Davy, but the latter makes him a prisoner during a subsequent fight in the town café. Jeff confesses to Cole's involvement, and the Range Busters, with the help of town banker Harrison, set a trap for Cole and his outlaw vigilantes.

Gold stages are being held up in the far west at a time when the U.S. government needs bullion, just before the famed "Black Friday" attempt to corner the gold market.

In this entry in the long-running series of westerns, the Three Mesquiteers transform their ranch into a prison farm to provide a model for prison reform. They are opposed by a local contractor who wants to build a standard prison.

The notorious outlaw Black Bart has reappeared and the Range Busters are sent to investigate. When they find that Black Bart is now a respectable citizen and that someone is impersonating him, they set a trap for the robber.

Agent Pete Garland is fired by society singer Monica Barrett after he got her a new radio contract, because she thinks her lawyer friend Teddy Leeds fits in better with her social status. To get even, Pete wants to make an unknown singer into a star. He finds Ruth Allison, drives her hard through rehearsals and makes her a star. But she is worried about her past, something she hasn't told Pete: She's an ex-convict and jumped bail in order to keep her partners in crime out of it. Further she's in love with Pete, but feels that he's still carrying a torch for Monica. When Monica's popularity is decreasing, Pete is able to get Ruth a stint on the program, the result is Monica is fired and Ruth get her job, but Monica takes revenge by revealing Ruth's past. Ruth considers it is best for her to disappear before being arrested, but she has become a star in public opinion. Will she get Pete or will she go to prison again?

The three Mesquiteers try to recover the gold stolen by a gang in its effort to ruin the banker/mayor who ordered them to leave town.

Hammond is after the Craig ranch and has framed Charlie Craig for murder. Mother Craig brings in the Range Busters. They capture one of Hammond's men and Alibi plans to trick him into a confession as to who the real murderer is. Meanwhile, Denny has overheard Hammond's plans for his next move and he and Crash set out to round up the gang.

It is the story of Gene's, a Cavalry scout, who manages to quell an Indian uprising.

When Professor Marsh disappears while searching for the lost city of Lukachukai, his daughter enlists the help of the Three Mesquiteers.