<P> Located 35 miles (56 km) from Evans pass, Union Pacific connected the new "railroad" town of Cheyenne to Denver and its Denver Pacific Railway and Telegraph Company railroad line in 1870 . Elevated 6,070 feet (1,850 m) above sea level, and sitting on the new Union Pacific route with a connection to Denver, Cheyenne was chosen to become a major railroad center and was equipped with extensive railroad yards, maintenance facilities and a Union Pacific presence . Its location made it a good base for helper locomotives to couple to trains with snowplows to help clear the tracks of snow or help haul heavy freight over Evans pass . The Union Pacific's junction with the Denver Railroad with its connection to Kansas City, Kansas, Kansas City, Missouri and the railroads east of the Missouri River again increased Cheyenne's importance as the junction of two major railroads . Cheyenne later became Wyoming's largest city and the capital of the new state of Wyoming . </P> <P> The railroad established many townships along the way: Fremont, Elkhorn, Grand Island, North Platte, Ogallala and Sidney as the railroad followed the Platte River across Nebraska territory . The railroad even dipped into what would become the new state of Colorado after crossing the North Platte River as it followed the South Platte River west into what would become Julesburg before turning northwest along Lodgepole Creek into Wyoming . In the Dakota Territory (Wyoming) the new towns of Cheyenne, Laramie, Rawlins (named for Union General John Aaron Rawlins, who camped in the locality in 1867 .), Green River and Evanston (named after James Evans) were established, as well as many more fuel and water stops . The Green River was crossed with a new bridge, and the new "railroad" town of Green River constructed there after the tracks reached the Green River on October 1, 1868--the last big river to cross . </P> <P> On December 4, 1868, the Union Pacific reached Evanston, having laid almost 360 miles (580 km) of track over the Green River and the Laramie Plains that year . By 1871, Evanston became a significant maintenance shop town equipped to carry out extensive repairs on the cars and steam locomotives . </P> <P> In the Utah Territory, the railroad once again diverted from the main emigrant trails to cross the Wasatch Mountains and went down the rugged Echo Canyon (Summit County, Utah) and Weber River canyon . To speed up construction as much as possible, Union Pacific contracted several thousand Mormon workers to cut, fill, trestle, bridge, blast and tunnel its way down the rugged Weber River Canyon to Ogden, Utah, ahead of the railroad construction . The Mormon and Union Pacific rail work was joined in the area of the present - day border between Utah and Wyoming . The longest of four tunnels built in Weber Canyon was 757 - foot - long (231 m) Tunnel 2 . Work on this tunnel started in October 1868 and was completed six months later . Temporary tracks were laid around it and Tunnels 3 (508 feet (155 m)), 4 (297 feet (91 m)) and 5 (579 feet (176 m)) to continue work on the tracks west of the tunnels . </P>

Who did most of the work building the transcontinental railroad