Desc: Riders of the Black Hills: Directed by George Sherman. With Robert Livingston, Ray Corrigan, Max Terhune, Ann Evers. The famous race horse Black Knight has been stolen and a ransom is being asked. The Mesquiteers become involved when they are arrested for the theft. Mrs. Garth clears them and their look-alike horse is then used in the big race posing as Black Knight. When he wins the kipnapers now demand the entire purse.