Question: Where is the headquarters of the railroad for which the Union Pacific 4466 was built located?

Context articles: History of railroads in Colorado
Union Station (Seattle)
Union Pacific 4466
Feather River Route
Union Pacific 844
Union Pacific Challenger
Union Pacific Railroad
Central Branch Union Pacific Railroad
Union Pacific Police Department
Kansas Pacific Railway

The history of rail transportation in Colorado began with the competition between two separate railways in the late 1860s the Denver Pacific Railroad and the Colorado Central and Pacific Railroad.
 Following the decision of the Union Pacific Railroad to route the transcontinental railroad through Cheyenne, Wyoming instead of Denver, the first town in the Front Range area to construct a connecting line to the Union Pacific Railroad would more naturally become the economic focus of the Colorado territory.
 The Colorado Central and Pacific Railway was incorporated in 1865 by residents of Golden, however this railway was unable to immediately begin constructing a connecting line to Cheyenne.
 The existence of the Colorado Central and Pacific Railroad prompted the citizens of Denver to incorporate the Denver Pacific Railroad on November 19, 1867.
 Following a spirited campaign raising capital, the Denver Pacific Railroad laid its first track in 1869.
 By June 26, 1870, the Denver Pacific Railroad was completed.
Union Station is a former train station in Seattle, Washington, United States, constructed between 1910 and 1911 to serve the Union Pacific Railroad and the Milwaukee Road.
 It was originally named Oregon and Washington Station, after a subsidiary line of the Union Pacific.
 Located at the corner of S. Jackson Street and 4th Avenue S. in the Pioneer Square neighborhood, the station opened on May 20, 1911.
 The Milwaukee Road discontinued passenger service to Union Station 50 years later, on May 22, 1961, and the Union Pacific followed suit on April 30, 1971.
 With no passenger rail service serving Seattle from Union Station, the building remained largely empty.
 After nearly 30 years of sitting idle, the station finally experienced an expansive renovation supported by Nitze-Stagen with financial backing from Paul Allen.
 The Union Station renovation was the winner of the 2000 National Historic Preservation Award.
 It now serves as the headquarters of Sound Transit; its grand hall is rented out to the public for weddings and other events.
Union Pacific 4466 is an 0-6-0 type steam locomotive built in October 1920 for the Union Pacific Railroad (UP) to perform switching chores and transfer runs.
 4466 spent most of its career in Cheyenne, Wyoming, as a shop switcher and was the UP Cheyenne Shop's last steam shop switcher.
 After its stint in Cheyenne, 4466 was transferred to Grand Island, Nebraska, remaining there until 1973.
 it was donated to California State Railroad Museum in 1978.
 In 1984, it was restored to service and pulled museum excursions.
 In 1986, 4466 ventured to Vancouver, British Columbia, to be part of .
 4466 now resides in retirement.
 It has been sold to the Niles Canyon Railroad to be restored to service.
 As of 2016, the locomotive is at the California State Railroad Museum, in two pieces, preparing to be shipped by truck.
The Feather River Route is a rail line that was built and operated by the Western Pacific Railroad.
 It was constructed between 1906 and 1909, and connects the cities of Oakland, California, and Salt Lake City, Utah.
 The line was built to compete with the Central Pacific Railroad (and later Southern Pacific Railroad), which at the time held a nearly complete monopoly on Northern California rail service.
 The route derives its name from its crossing of the Sierra Nevada, where it follows both the North and Middle Forks of the Feather River.
 The route is famous for its impressive engineering qualities and its considerable scenic value.
 All of the route is now owned and operated by the Union Pacific Railroad; however, the Union Pacific has transferred significant portions of the route to other lines.
 The portion still called the Feather River Route by the Union Pacific runs from the California Central Valley to Winnemucca, Nevada.
Union Pacific 844 is a 4-8-4 "Northern" type steam locomotive built by the American Locomotive Company in December 1944 for the Union Pacific Railroad.
 Constructed as a member of the FEF-3class of 4-8-4's, the 844 was the last steam locomotive delivered to Union Pacific.
 Though the FEF-3 class was originally built for high-speed passenger work, 844 and the rest of the FEF-3 class were pressed into a variety of dual-service work.
 While commercial Union Pacific steam operations ended in the late 1950s, 844 was retained by the railroad for special activities.
 Today, it is one of UP's oldest serving locomotives, as well as the only steam locomotive never retired by a North American Class I railroad.
The Union Pacific Challengers were a type of simple articulated 4-6-6-4 steam locomotive built by American Locomotive Company for the Union Pacific Railroad.
 105 of these locomotives were built between 1936 and 1943.
 The Challengers were nearly 122 ft long and weighed 314 tons (284,800 kg).
 They operated over most of the Union Pacific system, primarily in freight service, but a few were assigned to passenger trains operating through mountain territory to California and Oregon.
 The locomotives were built specifically for Union Pacific and much of the experience gained later went into the design of the "Big Boy".
The Union Pacific Railroad (or Union Pacific Railroad Company and simply Union Pacific) is a freight hauling railroad that operates 8,500 locomotives over 32,100 route-miles in 23 states west of Chicago and New Orleans.
 The Union Pacific Railroad system is the largest in the United States and it is one of the world's largest transportation companies.
 The Union Pacific Railroad is the principal operating company of the Union Pacific Corporation (); both are headquartered in Omaha, Nebraska.
The Central Branch Union Pacific Railroad was a railroad in the U.S. state of Kansas.
 Originally planned as a line from Atchison west into Colorado, and given federal land grants by the Pacific Railway Act of 1862 as one of the branches of the Union Pacific Railroad, it was left with a hanging end at Waterville, Kansas when the Union Pacific Railway, Eastern Division, with which it was to connect, changed its route.
 The line was acquired by the Union Pacific through a stock purchase by Jay Gould and leased to the Missouri Pacific Railroad in 1880.
 In 1909 the Central Branch was merged into the Missouri Pacific; the latter company came back into the Union Pacific system in 1982.
 In 1991 the remaining trackage west of Frankfort was leased to the Kyle Railroad.
The Union Pacific Police Department is the law enforcement agency of the Union Pacific Railroad.
 Its headquarters is in Omaha, Nebraska and its current Chief of Police is Robert Morrison.
 The railroad police force dates to the 1850s, when the number of U.S. Marshals was insufficient to police America's growing rail network.
 U.S. Marshals were replaced with a private police company, the North-Western Police Agency, later known as the Pinkerton Agency.
 Officers were called Pinkertons, named after their originator, Allan Pinkerton, who founded the private police company in 1855 with Chicago attorney Edward Rucker.
 Today, the Union Pacific Police Department is one of the sixteen Class I railroad law enforcement agencies across the country.
The Kansas Pacific Railway (KP) was a historic railroad company that operated in the western United States in the late 19th century.
 It was a federally chartered railroad, backed with government land grants.
 At a time when the first transcontinental railroad was being constructed by the Central Pacific and the Union Pacific, it tried and failed to join the transcontinental ranks.
 It was originally the "Union Pacific, Eastern Division", although it was completely independent.
 The Pennsylvania railroad, working with Missouri financiers, designed it as a feeder line to the transcontinental system.
 The owners lobbied heavily in Washington for money to build a railroad from Kansas City to Colorado, and then to California.
 It failed to get funding to go west of Colorado.
 It operated many of the first long-distance lines in the state of Kansas in the 1870s, extending the national railway network westward across that state and into Colorado.
 Its main line furnished a principal transportation route that opened up settlement of the central Great Plains, and its link from Kansas City to Denver provided the last link in the coast-to-coast railway network in 1870.
 The railroad was consolidated with the Union Pacific in 1880, and its mainline continues to be an integral part of the Union Pacific network today.