Union Pacific's Big Boy #4014 glides across the plains east of Hugo, Colorado as it runs towards Denver.

Union Pacific Big Boy #4014 (4-8-8-4) gets ready to leave the UP's North Yard in Denver, Colorado and will heads back to home base in Cheyenne, Wyoming.

Union Pacific Big Boy #4014 leaves the Denver skyline behind as it heads towards Commerce City on the way back to home base in Cheyenne, Wyoming.

UP Big Boy #4014 (4-8-8-4) crosses a bridge west of Hugo, Colorado as the locomotive heads to Denver on the old Kansas-Pacific rail line.

Union Pacific's Big Boy #4014 backs under the signal bridge in Cheyenne, Wyoming as it finishes its second trip of the year.

Union Pacific's Big Boy #4014 (4-8-8-4) runs over a bridge spanning a wide arroyo in Peoria, Colorado.

Union Pacific's Heartland of America Tour with #4014 leading the way crosses Little Bijou Creek at Peoria, CO on the Limon sub.

Sunrise catches Union Pacific's Big Boy #4014 (4-8-8-4) as it gets ready to leave Sharon Springs, Wyoming for Denver, Colorado on the old Kansas Pacific line.

This summer, I had the privilege to witness UP 4014, Union Pacific's restored "Big Boy" 4-8-8-4 steam locomotive, ply the rails of the UP mainline once again, this time leading the "... (more)

This summer, I had the privilege to witness UP 4014, Union Pacific's restored "Big Boy" 4-8-8-4 steam locomotive, ply the rails of the UP mainline once again, this time leading the "... (more)

Union Pacific Big Boy #4014 backs into the large yard in Cheyenne, Wyoming as it winds up its successful second trip of the year.

Union Pacific Big Boy #4014 heads towards Speer, Wyoming on its return trip to the home shops in Cheyenne.

This summer, I had the privilege to witness UP 4014, Union Pacific's restored "Big Boy" 4-8-8-4 steam locomotive, ply the rails of the UP mainline once again, this time leading the "... (more)

This summer, I had the privilege to witness UP 4014, Union Pacific's restored "Big Boy" 4-8-8-4 steam locomotive, ply the rails of the UP mainline once again, this time leading the "... (more)

Union Pacific Big Boy #4014 runs through Speer, Wyoming as it heads back to the shops in Cheyenne.