<P> For the pilot episode, "The Night of the Inferno", the producers used Sierra Railroad No. 3, a 4 - 6 - 0 locomotive that was, fittingly, an anachronism: Sierra No. 3 was built in 1891, fifteen to twenty years after the series was set . Footage of this train, with a 5 replacing the 3 on its number plate, was shot in Jamestown, California . Best known for its role as the Hooterville Cannonball in the CBS series Petticoat Junction, Sierra No. 3 probably appeared in more films and TV shows than any other locomotive in history . It was built by the Rogers Locomotive and Machine Works in Paterson, New Jersey . </P> <P> When The Wild Wild West went into series production, however, an entirely different train was employed . The locomotive, a 4 - 4 - 0 named the Inyo, was built in 1875 by the Baldwin Locomotive Works in Philadelphia . Originally a wood - burner, the Inyo was converted to oil in 1910 . The Inyo, as well as the express car and the passenger car, originally served the Virginia and Truckee Railroad in Nevada . They were among V&T cars sold to Paramount Pictures in 1937--38 . The Inyo appears in numerous films including High, Wide, and Handsome (1938), Union Pacific (1939), The Marx Brothers' Go West (1940), Meet Me in St. Louis, (1944), Red River (1948), Disney's The Great Locomotive Chase (1956) and McLintock! (1963). For The Wild Wild West, Inyo's original number plate was temporarily changed from No. 22 to No. 8 so the train footage could be flopped horizontally without the number appearing reversed . Footage of the Inyo in motion and idling was shot around Menifee, California, and reused in virtually every episode . (Stock footage of Sierra No. 3 occasionally resurfaced as well .) </P> <P> These trains were used only for exterior shots . The luxurious interior of the passenger car was constructed on Stage 6 at CBS Studio Center . (Neither Stage 6 or the western streets still exist .) Designed by art director Albert Heschong, the set reportedly cost $35,000 in 1965 (approximately $250,000 in 2011 dollars). The interior was redesigned when the show switched to color for the 1966 - 67 season . </P> <P> The train interior was also used in at least one episode of Gunsmoke ("Death Train," aired January 27, 1967), and in at least two episodes of The Big Valley ("Last Train to the Fair," aired April 27, 1966, and "Days of Wrath," aired January 8, 1968). All three series were filmed at CBS Studio Center and shared other exterior and interior sets . Additionally, the interior was used for an episode of Get Smart ("The King Lives?", aired January 6, 1968) and the short - lived Barbary Coast ("Funny Money," aired September 8, 1975). </P>

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