More footage of the Union Pacific Challenger from the late 1980s and 90s. The Union Pacific Challenger #3985 has been donated to the RHMA (Railroading Heritage of Midwest America) to be moved to Silvis Illinois and restored to operating condition.
Back in the late 20th century, the Union Pacific Steam Program ran both Union Pacific #844 and #3985 in excursion service over much of the Union Pacific system.
Wickipedia:
Union Pacific 3985, also known as the "Challenger", is a four-cylinder simple articulated 4-6-6-4 "Challenger"-type steam locomotive built in July 1943 by the American Locomotive Company (ALCO) of Schenectady, New York, for the Union Pacific Railroad. No. 3985 is one of only two Challengers still in existence and the only one to have operated in excursion service.
No. 3985 operated in revenue service until 1957. It was then stored in the roundhouse in Cheyenne, Wyoming, until 1975, when it was placed outdoors beside the Cheyenne depot. In March 1981, after a group of Union Pacific employees restored the locomotive to operating condition, it was placed into excursion service as part of the Union Pacific's heritage fleet and became the world's largest operational steam locomotive. Mechanical problems took it offline in 2010, after which it was stored at the Union Pacific's Steam Shops in Cheyenne.
On May 1, 2019, the title of largest operational steam locomotive was passed to the newly restored 4-8-8-4 Union Pacific Big Boy No. 4014. Because of its poor mechanical condition, No. 3985 was officially retired from excursion service in 2020. In April 2022, UP officials announced that the company would donate the locomotive to the Railroading Heritage of Midwest America (RRHMA), which plans to restore it to operating condition.