BNSF 6037 (ES44AC) leads a freight into the BNSF yard in Golden, Colorado.

BNSF 3965 (ET44C4) leads a freight train out of the big yard in Denver, Colorado.

BNSF 2604 (GP39-3) heads to the yard in Longmont, Colorado to pick up the local train for Lafeyette, Colorado.

BNSF 2698 (GP39-3) pulls next to the Longmont Depot to pick up orders before heading to the yard.

BNSF 2371 (GP38-2) in Heritage I paint heads into the Denver Yard to sort cars.

BNSF 2745 (GP39E) in Cascade Green BN paint works the Denver Yard sorting cars.

UP 7788 (C45ACCTE) leads the GJ train through Leyden, Colorado on the Moffat Tunnel Sub.

UP 7634 (ES44AC) rounds the corner at Rocky, Colorado as it heads west into a bright sunset on the Moffat Tunnel Sub.

Union Pacific's Western Pacific heritage engine #1983 waits for orders after being serviced at the North Yard in Denver, Colorado.

The snow clouds are breaking up as Union Pacific 6891 (AC4400CW) muscles a freight towards Arvada, Colorado.

Union Pacific's Big Boy #4014 (4-8-8-4) runs through Speer, Wyoming as it returns to its home base at Cheyenne.

The sun is setting as the Colorado Railroad Museum's Denver & Rio Grande Western Railroad's #491 (2-8-2) heads to the depot where it will give rides as part of the annual Polar Express train. The... (more)

Amtrak engine #168 (P42DC) leads the California Zephyr through Tolland, Colorado on the Moffat Tunnel Sub.

BNSF 6149 (ES44AC) leads a freight through Pinecliffe, Colorado on the Moffat Tunnel Sub.

BNSF 1958 (SD40-2) in old school Cascade Green BN paint leaves the bowl in the yard in downtown Denver, Colorado.