UP 4533 (SD70M) leads an officer's special towards the Moffat Tunnel, passing the trusty designated chase vehicle dubbed "The F-Unit".

BNSF 2749 (GP39E) shoves a light motor run towards Lyons, Colorado where the crew will lash up to a small cut of empty hoppers to take back to Longmont.

BNSF 2749 (GP39E) sits at the Longmont Depot with the crew getting ready to head to the cement plant at Lyons, Colorado.

BNSF 8529 (SD70ACe) leads a coal train through Keenesburg at sunrise.

A bright orange sunrise glints off the stainless steel of the California Zephyr as it runs through Keenesburg, Colorado.

BNSF 2749 (GP39E) runs through the trees at Lyons, Colorado.

UP 8530 (SD70ACe) leads a quartet of power out of Tunnel #1 at Plainview, Colorado and will drop down into Coal Creek Canyon.

A Union Pacific Officer Special gets ready to leave the North Yard in Denver, Colorado and will run into the Colorado Rockies for the Moffat Tunnel.

A keyhole in the clouds allows a spotlight of sun to shine on a Union Pacific Officer Special as it runs through Coal Creek Canyon, Colorado.

A Union Pacific Officer Special runs towards the evening sun as it gets ready to enter the Moffat Tunnel at Tolland, Colorado.

A Union Pacific Officer Special runs through Rocky, Colorado as it begins the journey into the Colorado Rocky Mountains on the Moffat Tunnel Sub.

UP 8530 (SD70ACe) leads a freight down the hill from Tunnel #1 and into Coal Creek Canyon, Colorado as it heads to Denver on the Moffat Tunnel Sub.

The California Zephyr runs through Keenesburg, Colorado at sunrise.

BNSF 2749 (GP-39E) runs from Lyons, Colorado to Longmont with a short cut of hoppers.

DRGW 5771 (F9A) had a storied career in Colorado, leading the Rio Grande Zephyr until 1983, when it was then used for some time leading the Colorado Ski Train, and she even ran some freight before... (more)