A colorful Canadian National AC44C6M leads a grain train at Hillrose, Colorado.

BNSF 1879 (SD39-2) is spotted working the BNSF yard in Sterling, Colorado.

BNSF 9155 (SD70ACe) reflects off of Barr Lake as it leads a coal train on the Brush Sub past Barr Lake in Brighton, Colorado.

BNSF 8766 (SD70ACe) muscles a coal train through Hillrose, Colorado as it heads to Sterling.

BNSF 7599 (ES44DC) waits on a siding in Bragdon, Colorado for a new crew that will then take the train to Denver on the Joint Line.

BNSF 8593 (SD70ACe) leads a coal train towards Fountain, Colorado on the Joint Line.

A blackbird photo bombs Amtrak engine 151 as it leads the California Zephyr through the Denver Yard and to Denver's Union Station.

The California Zephyr #6 train rounds the Big Ten Curve in Rocky, Colorado as it heads to Denver on the Moffat Tunnel Sub.

BNSF 8766 (SD70ACe) passes another coal train and a 0-4-0T 'Dinky' tank engine in Sterling, Colorado.

BNSF 4251 (ES44C4) leads the Z Train east on the Brush Sub through Fort Morgan, Colorado.

Cell phone towers dominate the landscape in Akron, Colorado as the California Zephyr runs east on the Brush Sub towards Denver.

CN 3321 (AC44C6M) leads a grain train through Hillrose, Colorado and will eventually arrive in Denver for a crew change.

CN 3321 (AC44C6M) leads a grain train and passes a coal train which will release and head to Sterling, Colorado.

The crew of a grain train headed by CN 3321 (AC44C6M) ties down at Hillrose, Colorado as the crew van awaits.

Amtrak engine #147 (P42DC) leads the California Zephyr through Akron, Colorado at sunrise.