The California Zephyr pulls into the historic station in Glenwood Springs, Colorado.

The California Zephyr runs through Keenesburg, Colorado as a golden sunrise glints off the side of the engines.

The California Zephyr #5 train runs through Coal Creek Canyon on the Moffat Tunnel Sub.

BNSF 8115 (ES44C4) runs through Caste Rock, Colorado as it heads south on the Joint Line.

BNSF 6339 (ES44AC) leads a freight downhill from Tunnel #1 into Coal Creek Canyon, Colorado.

BNSF 6014 (ES44AC) runs past a frozen Palmer Lake as it heads south on the Joint Line.

BNSF Executive Grinstein #9709 (SD70MAC) is well known in the Denver area for making the Beer Train run between the Coors Brewery in Golden, Colorado and the yard in Denver.

BNSF 7853 (ES44DC) runs south on the Joint Line through Sedalia, Colorado.

UP 8834 (SD70AH) leads an oil train through Coal Creek Canyon after having dropped down from Tunnel #1 on the Moffat Tunnel Sub.

UP 8006 (ES44AC) leads a power heavy train south on the Greeley Sub through Platteville, Colorado.

UP 7425 (ES44AC) runs a hopper train through the North Yard in Denver, Colorado.

UP 8834 (SD70AH) leads an oil can train towards Leyden, Colorado as it heads to Denver on the Moffat Tunnel Sub.

BNSF 1532 (GP28-2) repositions in a busy Denver Yard where it will work side by side other units sorting freight cars.

The California Zephyr through Tolland, Colorado as it heads to the Moffat Tunnel and the Rocky Mountains.

Amtrak engine #163 (P42DC) leads the California Zephyr through the corner at Tolland, Colorado.