Union Pacific 4466 is an 0-6-0 type steam locomotive built in October 1920 for the Union Pacific Railroad to perform switching chores and transfer runs. 4466 spent most of her career in Cheyenne, Wyoming as a shop switcher and was the UP Cheyenne Shop's last steam shop switcher. After her stint in Cheyenne, 4466 was transferred to Grand Island, Nebraska, remaining there until 1973. She was donated to California State Railroad Museum in 1978. In 1984, she was restored to service and pulled museum excursions. In 1986, 4466 ventured to Vancouver, British Columbia to be part of Steam Expo '86. In 1999, new California emissions regulations banned the operation of coal-fired steam locomotives, forcing the 4466 out of service indefinitely. 4466 is now a static display with no plans to return her to operation.