Renegades of the Rio Grande is an exciting Western made in 1945. When a gang of bank robbers murders his family member, Buck (Rod Cameron) infiltrates the gang in an attempt to find out where they stashed their loot and get even. Texas Rangers Cal Benedict (Eddie Dew) and Trigger Bidwell (Fuzzy Knight) witness the murder and apparent abduction of Buck and free the kidnapped man. They then begin to tail and investigate Buck, unsure if he is involved with the robbers or not. Buck heads to the ranch where he has discovered the loot is stashed, still followed by the Rangers. The ranch is owned by Dolores (Jennifer Holt), who becomes a love interest for Buck. What follows is Buck's attempt to convince Dolores and the Texas Rangers of his own innocence, while completing his plot to take revenge on the robbers, without ending up another one of their victims.