“Reign of the Gila Monster” by L. Ron Hubbard
Publication date: September 1937
Original publication: Western Aces
Story description: Howdy Johnson may not be a sharp shooter, but he is a brave sharp thinker, which is good enough to rid Powderville of its murderous, fast shooting sheriff.
Currently available as part of the Stories from the Golden Age series, in the title The Baron of Coyote River.