July 23, 1959

Last Steam Locomotive Runs from North Platte to Cheyenne

Union Pacific at one time owned 105 Challenger locomotives. Built between 1936 and 1943, the Challengers were nearly 122 feet long and weighed more than one million pounds. Articulated like their big brother, the Big Boy, the Challengers had a 4-6-6-4 wheel arrangement. They operated over most of the Union Pacific system, primarily in freight service, but a few were assigned to passenger trains operating through mountain territory to California and Oregon. As the efficiency of diesels overtook steam, UP relegated its Challengers to the Wyoming lines beginning in the mid-1950s.

Event Media

Today, one of two remaining Challengers, No. 3977, is on display in North Platte, Neb. The other, Challenger No. 3985, was restored to operating condition by Union Pacific employee volunteers and is kept by UP for excursion service.

In 2012, Union Pacific celebrates the shared stories that have shaped our country since 1862. To mark our 150th anniversary, we invite you to explore how the nation’s largest railroad came to be and how UP continues to build America with innovation and tenacity, touching the lives of nearly every citizen.