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.
| Actor | Role |
|---|---|
 Robert LivingstonStony Brooke | Stony Brooke |
 Ray CorriganTucson Smith | Tucson Smith |
 Max TerhuneLullaby Joslin | Lullaby Joslin |
 Priscilla LawsonMadeline Reynolds | Madeline Reynolds |
 LeRoy MasonRed | Red |
| JJames EaglesThe Kid | The Kid |
 Roy BarcroftRobert Beaton | Robert Beaton |
| BBarry HaysBeaton's Cohort | Beaton's Cohort |
 Carleton YoungConnors | Connors |
 Forrest TaylorSheriff | Sheriff |
| JJohn P. WadeBoard Chairman (as John Wade) | Board Chairman (as John Wade) |
| MMaston WilliamsConvict | Convict |
| JJohn BeachHenchman Crane | Henchman Crane |
| JJerry FrankConvict Slim | Convict Slim |
 Roger WilliamsThe Warden | The Warden |