The sleek lines of the UP 4014 Big Boy engine are apparent in this view as the behemoth heads towards Strasburg, Colorado.

Steaming out of Strasburg. Union Pacific 4014 is seen crawling out of Strasburg, CO after a brief stop en route to Denver. The low-speed departure is due to the large crowd that came to ... (more)

UP Big Boy 4014 leaves Sharon Springs amid a cloud of steam and threatening skies as onlookers get one more photo.

Union Pacific Big Boy 4014 crosses over a bridge in Bennett, Colorado. It will soon be in Denver and be put on display for all to see on labor day.

Steaming into Denver. Union Pacific 4014 charges into Denver, approaching the Havana St grade crossing. Getting this shot involved a quick driver swap in the median of Havana St so I cou... (more)

The Main Event! Union Pacific 4014 arrives to a huge crowd in Strasburg, Colorado en route to Denver. This penultimate leg of the Big Boy's summer tour drew spectators from all over Colo... (more)

A month-long trip is in its final miles as #4014 heads up the hill to the junction at Speer and into Cheyenne. #1989 was part of the display event in Denver, it will lead the passenger cars east ... (more)

UP Big Boy 4014 leaves Sharon Springs as sun rays peak through holes in the clouds.

'UP 4014 Big Boy on Golden Pond'. The lighting conditions were such that between the smoke filled skies and the bright sunrise, a golden glow bathed the Union Pacific's Big Boy for about 5 minu... (more)

The gritty vibe of the refineries in Commerce City, Colorado lends itself to imagining what the Big Boy would have looked like 70 years ago leaving Denver and heading home to Cheyenne, Wyoming.

Dawn is breaking at Sharon Springs, Kansas as the crew starts to prep UP 4014 for the run to Denver, Colorado.

Union Pacific Big Boy 4014 runs between the cottonwood trees at Aroya, Colorado.

The "Big Boy" arrives in St. Louis during its 2021 Tour.