UP 1980 (GP38N) waits in the Union Pacific's North Yard in Denver, Colorado for service at the fuel islands.

UP 4363 (SD70M) works the siding in Platteville, Colorado on the Greeley Sub.

UP 8719 (SD70ACe) exits the west portal of the Hermosa Tunnel with a plumb of smoke.

Light snow falls at Tie Siding, Wyoming as UP 2540 (ES44AC) leads a stack train north towards Laramie.

UP 6393 (AC4400CW) exits a snowy east portal of the Hermosa Tunnels as it heads to Cheyenne, Wyoming.

UP Ace 8719 leads a freight out of the Yard early in the morning as the snow falls in Cheyenne, Wyoming.

The snow is falling fast as UP 6417 (AC4400CW) brings a stack train into the east end of the Union Pacific yard in Chyenne, Wyoming.

The crew of BNSF 2549 (GP39-3) makes a stop at the Longmont Depot to add some water before heading to the yard.

BNSF 6928 (ES44C4) leads a stack train through the S curve in Monument, Colorado.

BNSF 6015 strains to pull a loaded coal train around the horseshoe curve in Palmer Lake, Colorado.

BNSF 6928 (ES44C4) leads a stack train through the trees at Palmer Lake on the Joint Line.

The California Zephyr climbs the grade out of Coal Creek Canyon and heads towards Tunnel #1 on the Moffat Tunnel Sub.

UP 1507 (GP40M) is entering the BNSF's Denver Yard with a cut of freight cars and will head back to the UP North Yard after dropping off the cars.

UP 1507 (GP40M) moves a cut of cars early in the morning in the Union Pacific's North Yard in Denver, Colorado.

UP 6047 (AC4400CW-CTE) splits the signals just east of Hot Sulphur Springs, Colorado.