Information from the brochure produced by the City of North Platte and the North Platte/Lincoln County Convention & Visitors Bureau
Union Pacific Museum & Depot Display in Cody Park
The Challenger Engine #3977 was delivered to the Union Pacific Railroad in June 1943. Of the 105 such monster "3900" class locomotives built by American Locomotive Company of New York, only two remain. The only one in the world on public display is here.
These engines were designed for both freight and passenger service, allowing for speeds up to 80 mph.