The Union Pacific's stations are something I did cover once before, but, I didn't have any luck back then in finding other impressive Union Pacific stations, until now. The U.P. West Yellowstone Dining Hall

In 1905, E. H. Harriman, president of the Union Pacific Railroad, traveled through Yellowstone National Park to meet with officials from the Northern Pacific Railroad. They discussed the growing needs of the increasing numbers of park visitors. Then Harriman ordered the construction of a rail line from St. Anthony, Idaho (the terminus of the Union Pacific Line at that time) to the park’s western border in Montana. This line was managed by the Oregon Short Line, a subsidiary of the Union Pacific Railroad.

Work on grading and laying rails began late in 1905. By January of 1906, the entire alignment for the railroad from St. Anthony to West Yellowstone was established. Shortly thereafter, the Union Pacific line was opened to West Yellowstone in 1907, it was the most popular access point, garnering over 50% of all train passengers coming to the park.

https://www.weddingwire.com/biz/union-pacific-dining-lodge-west-yellowstone/8d9952cb73193841.html

The Union Pacific Depot is the oldest remaining structure in the Oregon Short Line Historic District. The depot was completed in 1909, replacing a temporary wooden structure that served as the depot in 1908. The station was designed by the Union Pacific Railroad’s Engineering Office.

According to the Historic Yellowstone Center, people came on the train by the thousands in the early part of the 20th century on a branch out of Idaho that was only open for a few months in the spring and summer each year.

Snow closed the line every winter from its start in 1908 until the demise of passenger service in 1960. Amazingly, sporadic freight service continued as late as 1979. The rails came up in 1981, and apparently a goodly portion of the line is a rail trail.

http://cs.trains.com/trn/b/staff/archive/2015/08/20/a-trip-out-west-part-3-union-pacific-s-yellowstone-connection.aspx
https://www.yellowstonehistoriccenter.org/depot/
https://www.yellowstonehistoriccenter.org/trains/
https://explorebig.org/items/show/67?tour=3&index=9
http://bigskyjournal.com/trains-of-discovery/

here is the post I did on the Union Pacific train depot in Caliente a couple months ago https://justacarguy.blogspot.com/2018/08/caliente-nevada-least-populated.html