1. Home
 ›
2. Fallen Flags
 ›
3. Union Pacific
 ›
4. Steam Roster

Union Pacific Steam Roster: Post 1900

Last revised: October 3, 2024

By: Adam Burns

If you were a railfan in the 1950s, Union Pacific was a great place to catch everything from 2-8-0s on rural branch lines to powerful and legendary 4-8-8-4 "Big Boys" hustling expedited freights over Sherman Hill.

Throughout the 20th century, which is the focus of this steam roster, UP continually looked to larger and more powerful designs to handle trains more efficiently. 

It also operated a large fleet of articulated designs to handle the mountain grades west of Cheyenne; aside from the Big Boys this included 4-6-6-4s, 2-8-8-0s, and 2-8-8-2s.  It also maintained large fleets of 2-10-2s, 4-8-4s, and even the unique 4-12-2 for fast freight service.

Union Pacific, forged in the crucible of America's westward expansion, stands as one of the most iconic symbols of industrial and economic progress. Chartered by Congress through the Pacific Railway Act of 1862, under President Abraham Lincoln's administration, Union Pacific was part of an ambitious vision to connect the burgeoning eastern United States with the vast and untamed western territories.

The construction journey commenced in 1863 in Omaha, Nebraska. Financial backing emerged primarily from bonds issued by the federal government, complemented by substantial land grants.

With these resources, UP began its arduous task, laying track across the Great Plains and surmounting formidable natural obstacles such as the Rocky Mountains. 

Thomas C. Durant, a leading figurehead and vice president of the Union Pacific, played a vital role despite being enshrouded in controversy for his financial machinations.

The completion year of 1869 marked a watershed moment: the Golden Spike ceremony at Promontory Summit, Utah, symbolizing the joining of Union Pacific's eastern segment with the Central Pacific Railroad from the west. This event heralded the advent of a transcontinental railway, radically transforming American commerce and settlement patterns.

Throughout the late 19th and early 20th centuries, Union Pacific expanded through acquisitions and mergers, gradually weaving a tapestry of rail lines that penetrated deep into the American landscape. The railroad was instrumental during both World Wars, facilitating the rapid movement of troops and materials.

In contemporary times, Union Pacific has transformed into a freight-hauling titan. Modernization efforts, including dieselization and technological advancements in logistics and safety, have ensured its continued relevance.

Today, it commands one of the most extensive rail networks in North America, epitomizing the pioneering spirit that fueled its inception while driving the economic engine of an ever-evolving nation.

Union Pacific 4-12-2 #9062 leads Extra 9062 westbound west of Durham, Wyoming as the train nears Cheyenne, on August 31, 1955. John Shaw photo. American-Rails.com collection.

Switchers

A head-end view of Union Pacific 4-8-8-4 "Big Boy" #4016 at Rawlins, Wyoming on September 3, 1956. John Shaw photo. American-Rails.com collection.

Freight Locomotives

Passenger Locomotives

Union Pacific 4-8-4 #823 departs Denver, Colorado at 5 PM with train #86, the eastbound "National Parks Special" on July 3, 1950. The train is bound for Omaha, and then heads on to Chicago via the Chicago & North Western. American-Rails.com collection.

Articulated Designs