Union Pacific 4-8-8-4 4014 is the largest, heaviest, and most powerful operational steam locomotive in the world. Between 1941 and 1944 the American Locomotive Company built 25 of these large locomotives, originally to be called "Wasatch" engines, but before delivery, they were dubbed "Big Boy" locomotives. (They should have stuck with "Wasatch," in my opinion.) UP was the only purchaser of these 4-8-8-4s, designed to haul long freights over the Wasatch Mountains between Ogden UT and Green River WY (and later reassigned to as far east as Laramie WY) and they lasted in service until 1959. Of the 25 engines built, eight of them were saved from the scrapper’s torch. In 2014, UP acquired 4014 from the RailGiants Train Museum in Pomona, California, and it was sent to Cheyenne for restoration to operable condition. In May 2019, in time for the sesquicentennial of the driving of the Golden Spike on the original Transcontinental Railroad, UP 4014 operated from Cheyenne to Ogden to attend the festivities. The engine is seen here at the UP's West Colton Yard in Colton, California, backing into the yard for two days of display before operating on fan trips between Colton and Barstow as part of the "Great Race Across the Southwest" trips. Note that this locomotive as both of its engines in the classic "rods down" position!