UP 8131 (ES44AC) waits on the Belt Line for a green that will allow it to head to the Greeley Sub.

As storm clouds roll by in the background, Rio Grande Southern #20 (4-6-0) poses with D&RGW 491 on the grounds of the Colorado Railroad Museum in Golden, Colorado.

BNSF 6012 (ES44AC) shoved a coal train past a waiting UP freight train waiting on the siding at Plainview, Colorado.

Light snow is falling as the California Zephyr 5 train leaves Denver and heads up the Moffat Tunnel Sub.

Heavy snow is falling fast as the crew of UP 8233 (ES44ACH) gets ready to drop off an oil can train on the ready track for a new crew to take up the Moffat Tunnel Sub.

UP 6789 (AC4400CW) leaves Plainview, Colorado as it heads towards Tunnel #1 and Coal Creek Canyon.

BNSF 2621 (GP39-3) sits with a Bluebonnet at the old Longmont Depot, in front of apartments that used to be the site of the Butterball turkey rendering plant.

Storm clouds are moving in as BNSF 1812 (SD39-2) delivers a cut of box cars to a customer in Golden, Colorado.

BNSF 9043 (SD70ACe) and a Grinstein SD70MAC deliver a string of cryo refrigeration cars to the Coors Brewery in Golden, Colorado.

The bright sunrise catches UP 8131 (ES44AC) holding a grain train next to the North Yard silo in Denver, Colorado.

UP 6454 (AC4400CW) leads a Union Pacific passenger train through the Big Ten Curve on the Moffat Tunnel Sub

UP 6454 (AC4400CW) leads a Union Pacific passenger train out of Tunnel #1 at Plainview, Colorado.

BNSF 1812 (SD39-2) takes a short string of cars to customers in Golden, Colorado.

Denver Rock Island Railroad's #02 (a former Mount Hood Railroad GP38-2) takes a string of oil can cars to a yard in central Denver, Colorado.

UP 6789 (AC4400CW) sits among the wild sunflowers at Plainview, Colorado, waiting for a BNSF coal train to pass on the main track.