Like those on the UP #480 and UP #481 pages of this website, Union Pacific #485 was built in 1902 by Burnham, Williams & Co., later incorporated as Baldwin Locomotive Works, as part of an order for twenty Consolidation (2-8-0) type locomotives built as Vauclain compounds (#1901-#1920). They were renumbered #480-#499 in 1915.
As built, #485 had 15½" x 30" high pressure and 26" x 30" low pressure cylinders. However, by the turn of the century, many US railroads were no longer investing in compounds and were converting those they owned to single-expansion locomotives. So, between 1910 and 1918, the 1901s were progressively simplified with 21" x 30" cylinders, #485 in June 1910. From about 1914, most of the 1901s were also progressively fitted with superheaters and many worked into the late 1950s.
#485 was donated to the City of Lexington, NE, in 1956. It is one of several early 20th Century Union Pacific Consolidations dotted across the Great Plains. You can see some of the others on the UP #237, UP #407, UP #437, UP #480 and UP #481 pages of this website.