This was the second episode for Duke Shannon played by Denny Miller, aired April 26, 1961, however it his the first episode with John McIntire as wagon master, Christopher Hale. His first appearance was with Ward Bond wagon master Major Seth Adams which aired January 25, 1961. It explains how Duke became a scout for Wagon Train.
Wagon Train Tracker: Reference is made to the nearby "Lost Baldwin Mine." There is a Lucky Baldwin Mine Historic site near San Bernadino, California, established 1874. (Reference is also made to the train having left Ortonville, but Ortonville, Calif. is west of San Bernadino, in Ventura County.) So the train must be heading west on the Gila Trail, in the vicinity of San Bernadino, east of Los Angeles.