BNSF 1665 (SD40-2) sits waiting for service at the BNSF engine facility in Denver, Colorado.

UP 1826 (SD40N) sits on a siding in east Denver as a freight motors past and heads to the 36th Street Yard.

UP 8995 (SD70AH) muscles a mega coal train down through Tolland, Colorado on the Moffat Tunnel Sub.

KCS 4709 (ES44AC) runs through Monument, Colorado as it heads south on the Joint Line towards Colorado Springs.

KCS 4709 (ES44AC) runs towards Larkspur, Colorado on the Joint Line.

BNSF 7872 (ES44DC) heads into the Keenesburg Cut with a stack train as it runs east on the Brush Sub.

Light snow falls on BNSF Warbonnet 724 (Dash9) as it waits for service in the engine facility in Denver, Colorado.

BNSF 1653 (SD40-2) runs light through the heavy snow in Golden, Colorado.

BNSF 4234 (ES44C4) waits for a green signal at Roggen, Colorado.

BNSF 8115 (ES44C4) heads into the S curves at Spruce, Colorado as it leads a stack train south on the Joint Line.

A heavy blanket of snow covers Crescent, Colorado as UP 2698 (ET44AH) rounds the corner with an oil can train destined for Denver.

Light snow and winds buffet the California Zephyr as it runs past houses at Crescent, Colorado.

Amtrak's Winter Park Express runs through light snow at Plainview, Colorado as it heads up to the ski resort on the other side of the Moffat Tunnel.

The California Zephyr exits Tunnel #1 and runs towards Plainview, Colorado on its way up the Moffat Tunnel Sub.

KCS 4709 (ES44AC) leaves Castle Rock, Colorado and heads to Larkspur while running south on the Joint Line.