Considering that it was released in 1951, it is better than most "B" westerns of the period. It has a Roman horse jump, a chariot race, a stage coach race, a horse race, a rodeo and not one but three fights between Allen and perennial heavy Roy Barcroft all crammed into its 67 minute running time. Of course Rex gets to sing a couple of songs too.
The story centers around a little girl's affection for Allen's horse Koko in a rodeo setting.
Playing Allen's sidekick is future TV superstar Buddy Ebsen who does his best with limited material. Mary Ellen Kay plays the heroine and in addition to Barcroft, veteran heavy Tris Coffin plays the chief baddie.
Even at this late stage in the "B" western genre, Republic was still turning out a better product than any of the other studios. "Rodeo King and the Senorita" clearly demonstrated this.