World's Largest Steam Locomotive to Spend Night in Yuma

Oct 15, 2019

A rolling piece of history will be chugging into the Desert Southwest on Tuesday.

Union Pacific's iconic steam locomotive Big Boy No. 4014 - the world's largest steam locomotive - will be spending the night in Yuma.

It arrives in Yuma at 4 p.m. at the train tracks on 10th Street and Arizona Avenue.  Mayor Doug Nicholls will be there to welcome Big Boy and its crew to Arizona.  The historic locomotive will roll out of town Wednesday morning at 9 a.m., heading for Mohawk, Arizona.

25 Big Boys were built exclusively for Union Pacific beginning in 1941. It was specifically designed to handle the steep terrain between Cheyenne, Wyoming and Ogden, Utah.  

Today, only eight remain in existence. No. 4014 is the only one still owned by Union Pacific.  It took more than two and a half years to restore the locomotive. 

This Big Boy recently completed a tour of the upper Midwest.  Then, in May, it made a return to Ogden for the 150th anniversary of the transcontinental railroad's completion.

A comprehensive route map and tour schedule, including No. 4014’s GPS location tracking information is available at Due to the dynamic nature of these operations, running times and scheduled stops are subject to change.