UP 4005 leads an eastbound manifest over Peru hill.

Inside the cab of Union Pacific Big Boy 4005, which is on display at the Forney Museum of Transportation.

Union Pacific 4005, takes up a lot of space in the Forney Transportation Museum in Denver, Colorado.

Union Pacific SD70M no. 4005 leads an eastbound manifest through the wide open spaces of the Wyoming Landscape on the Transcontinental Route.

At Union Pacific’s Kansas City Locomotive Facility, Terry T. Quinones repairs a speed recorder cable on the front HTCR truck of UP EMD SD70M No. 4005 on October 21, 2013.

Here we see the ‘front office’ of Big Boy UP 4005. The Forney Transportation Museum has designed the exhibit in such a way as to easily access the cab of the engine for this unique view. One... (more)

Union Pacific 4005 is one of 8 surviving 4-8-8-4 Big Boy locomotives and is the only Big Boy ever converted to burn oil for fuel. She is one of only three housed in an enclosed facility, and can ... (more)

The iconic Union Pacific shield and green marker lights greet you when looking into the face of a UP Big Boy. This behemoth steam engine measures 132 feet in length, weighs 1,250,000 lbs and puts... (more)

When looking inside the cab of a Big Boy, one can see how challenging it must be to keep this beast of a steam engine running. The men who ran these monster steam locomotives were certainly a ski... (more)

Housed inside the Forney Transportation Museum is one of the world’s largest steam engines, the famous Union Pacific Big Boy. With only 25 ever built, 7 still reaming in display and 1 about to ... (more)

A Roper to El Paso repositioning autorack train climbs the Lynndyl Sub main approaching Erda on March 20, 2015.

Immediately after the Challenger passed (the train can be seen near the signal in the distance), UP 4005 and two sisters blast westward with a manifest, passing the Platte Vally Terminal grain ele... (more)

Lots of room in the cab of a Bigboy!