BNSF 9201 (SD70ACe) joins a Warbonnet as they wait for service at the BNSF engine facility in Denver, Colorado.

BNSF 7728 (ES44DC) leads a stack train under the Park Avenue Viaduct as it gets ready to leave Denver on the Brush Sub.

It is great to see a SW8 working the industrial areas in Denver served by the Denver Rock Island Railroad.

UP 1507 (GP40M) sits waiting in the Union Pacific's North Yard for its turn to sort cars.

UP 5518 (C45ACCTE) brings the California Zephyr #6 into Denver, Colorado as it runs under the Park Avenue Viaduct. Once in the yard it will then back into Denver's Union Station.

UP 1957 (SD40N) runs with open doors in the Union Pacific's North Yard in Denver, Colorado.

BNSF 1579 (SD40-2) sits on the time out track at the BNSF engine servicing facility in Denver, Colorado.

Sunrise at the BNSF engine servicing facility in Denver, Colorado finds a Maintenance of Way team getting ready to head out on the Joint Line for track improvements.

UP 1381 (Ex Southern Pacific GP40-2) holds station in the North Yard in Denver, Colorado.

This is the headquarters of the Denver Rock Island Railroad located in north Denver, Colorado.

A peek into the Diesel House reveals Southern Pacific GE AC4400CW No. 309 on Track 3, along with several other Union Pacific locomotives on adjoining tracks, at UP’s former Rio Grande Burnham Sh... (more)

UPY 691 (GP15-1) has somehow escaped the rebuild or repaint program but looks great in the weathered paint.

Amtrak engine #54 leads the California Zephyr through the North Yard as it heads towards Denver's Union Station.

There are 42 engines waiting for service or assignments in the yard of the BNSF engine servicing facility in Denver, Colorado.

A Norfolk Southern pony joins other UP motors at the service island in the North Yard in Denver, Colorado.