Union Pacific Big Boy #4004

On the Lincoln Highway between Morrie and Rollins.

The fifth of 25 Big Boy locomotives built by Alco for the Union Pacific.


Big Boy 4004

This was the 5th of 25 Big Boys built by Alco for the Union Pacific. It logged over 1,000,000 miles before being retired.

Photo taken by J.R. Manning in August 2003



Street View 


The fifth of 25 Big Boy locomotives built by Alco for the Union Pacific. This unit was built in 1941 as were the other 19 built in the first group. Five more were built in 1944. Like its 24 brethren, 4004 saw all of its operation between Ogden, Utah and Wahsatch, Wyoming.

The Union Pacific was hauling freight over the Wahsatch mountain range, a grade of 1.14% with the steepest and highest grade being that of Sherman Hill. Even the powerful Challenger 4-6-6-4 locomotives needed helpers over the range, an expensive proposition, costly in both time and manpower. With storm clouds looming over Europe and Asia, the UPRR wanted to be prepared for the extra effort that would be required in the event the United States would participate in the threatened World War.

The Big Boy was designed to haul a 3600 ton train at 80 MPH over the mountain range. (It never ran that fast, the 80 MPH feature was built to give a safety margin, and the trains usually ran at speeds upward of 60 MPH.)

4004 went into service in 1941 and was retired in 1959, logging over 1,000,000 miles in its career. It was donated to the city of Cheyenne in 1963.

Update Log 

  • August 31, 2016: New Street View added by Bill Eichelberger
  • September 2, 2012: Added by J.R. Manning


  • J.R. Manning - Lugnuts969 [at] gmail [dot] com
  • Bill Eichelberger - wallyum [at] hotmail [dot] com