Rock River Renegades (1942)

In Old Wyoming, a gang is plundering stagecoaches of shipped currency and a crusading newspaper editor is trying to get the local marshal replaced, because of his apparent failure to catch the gang, which seems to disappear into thin air after every robbery. The situation escalates when one of the stage drivers is mortally wounded; so the marshal sends for his friends, the Range Busters, to help him catch the criminals. Meanwhile, even the marshal's fiancee, the editor's daughter, turns against him in favor of an aggressive agitator for law and order - who secretly is leading the robber gang.