KCS 4709 (ES44AC) leads a grain train south on the Joint Line through Palmer Lake, Colorado.

KCS 4709 (ES44AC) leads a grain train south on the Joint Line towards Larkspur, Colorado.

UP 1817 (SD40N) sits in the Union Pacific's North Yard in Denver, Colorado.

UP 1826 (SD40N) pulls up to the yard crew who will board as head to the north end of the yard.

I think Alfred Hitchcock would have liked this photo. UP 1826 (SD40N) works the Union Pacific's North Yard in Denver, Colorado as hundreds of birds circle, waiting for the chance to land on the tr... (more)

BNSF 8281 (ES44C4) shoves a freight eastbound on the Brush Sub through West Tonville, Colorado.

BNSF 2828 (GP39-2M) sits in the new snow at the Longmont Depot until called upon to take a freight to Broomfield, Colorado.

The Winer Park Express Ski Train exits Tunnel #1 and runs through a very frosty Plainview, Colorado.

The California Zephyr has left Denver, Colorado and runs through Arvada on the Moffat Tunnel Sub.

RTD 4037 (Hyundai Eagle P3) commuter rail train arrives from Denver International Airport as it drops down from the elevated track north of Denver's Union Station.

A Union Pacific oil can train is seen from inside a rock formation at Crescent, Colorado.

It's the blue hour in Denver, Colorado as UP 6999 (AC4400CW) leads an oil can train towards the 36th Street Yard.

The snow is so deep that UP 8051 (ES44AC) pushes a wall of snow ahead of the train as it heads to Denver, Colorado on the Moffat Tunnel Sub.

UP 8051 (ES44AC) has emerged from the Moffat Tunnel into a heavy snow storm and will slowly lead an oil can train towards Denver, Colorado.

A visiting BNSF motors sits among the Union Pacific motors in the UP's 36th Street Yard in Denver, Colorado.