Union Pacific 4466 is an S-6 class "Switcher" type steam locomotive, built in October 1920 by the Lima Locomotive Works (LLW) for the Union Pacific Railroad (UP) for switching and transfer runs.
No. 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 Cheyenne, No. 4466 was transferred to Grand Island, Nebraska in 1960. The locomotive was retired from revenue service in 1958. It continued to remain in storage at Grand Island until March 1973 when it was donated to the Railway and Locomotive Historical Society.
In June 1978, No. 4466 was donated to the California State Railroad Museum. In 1984, it was restored to operating service and pulled excursion trains for the museum. In 1986, 4466 ventured to Vancouver, British Columbia, to be part of . The engine and tender were loaded onto flatcars in Sacramento, and headed to Vancouver, via rail on a Union Pacific freight train. Once it arrived in Vancouver, the locomotive and tender were unloaded onto the tracks and fired up for a safety test before it could operate in Canada. At the conclusion of Expo 86, engine and tender were again loaded onto flatcars and moved back to the CSRM via Union Pacific. This was not the only time 4466 took part in such a celebration, as it later went to Sacramento (its current home) for Railfairs in 1991 and 1999.
In 1999, the 4466âÂÂs FRA boiler certificate expired. The CSRM decided not to pursue an overhaul, causing the 4466 to be retired and put on indefinite static display. In 2012 it took part in the Union Pacific's 150th anniversary celebration. As of 2023, it is on static display at the California State Railroad Museum. It was featured in the 2005 American film Memoirs of a Geisha.