Question: Which film was released earlier, Yellowstone Kelly or Under Proof?
Sentence (from "Yellowstone Kelly"): Yellowstone Kelly is a 1959 Western Technicolor film based upon a novel by Heck Allen (using his pen name Clay Fisher, which shows in the movie credits) with a screenplay by Burt Kennedy starring Clint Walker as Luther Sage "Yellowstone" Kelly, and directed by Gordon Douglas.
Relevant evidence: Yes