A golden sunrise at Wiggins, Colorado creates a sepia tone as the California Zephyr runs towards Denver on the Brush Sub.

A golden sunrise glints off the Amtrak Winter Park Express Ski Train as it leaves Denver for the ski slopes in the Rocky Mountains.

Storm clouds at sunset catch the California Zephyr #6 train passing by Barr Lake in Brighton, Colorado.

The Rocky Mountaineer passenger train has 4 engines running in a push me - pull you configuration as it takes a load of passengers on a short trip to Eisele, Colorado and then back to Denver.

OmniTRAX #4011 (GP40-2LW) leads a freight east out of Loveland, Colorado and is taking cars to Johnstown.

UP 1358 (GP40N) joins other light power at the North Yard in Denver, Colorado.

UP 5910 (AC4400CW-CTE) gets ready to lead an oil can train west on the Moffat Tunnel Sub into the Colorado Rocky Mountains.

UP 1507 (GP40N) works the North Yard in Denver, Colorado.

UPY 618 (GP15-1) works on shuffling a string of hoppers into the ladders in the North Yard in Denver, Colorado.

UP 2238 (GP38-2) waits in the Union Pacific's North Yard in Denver, Colorado for orders to hit the yard.

UP 8697 (SD70ACe) leads a coal train down the 2% grade at Eisele, Colorado as it runs towards Denver on the Moffat Tunnel Sub.

Snow falls in the Colorado Rocky Mountains as UP 9088 (SD70ACe) leads a freight through Tolland, Colorado on the Moffat Tunnel Sub.

UP 1837 (SD40-2) moves a flat car and an oil can deeper into the North Yard in Denver, Colorado.

Fog moves through a sunny UP North Yard in Denver, Colorado.

A BNSF Geep lashes up to a heavy in the engine servicing yard in downtown Denver, Colorado.