An SD70AH brings up the rear of a consist of locomotives running light through Glenwood Canyon during the last moments of sunlight in Glenwood Springs, CO on January 17, 2016.

Amtrak train 5, the westbound California Zephyr, cruises along next to the Colorado River just after its stop in Glenwood Springs, CO on January 17, 2016.

Amtrak train 5, the westbound California Zephyr, rolls through Glenwood Canyon just before its stop in Glenwood Springs, CO on January 17, 2016.

Running as train P94 on the return trip from Winston-Salem, GP59 number 4612 leads a set of locomotives in Greensboro, NC on December 23, 2015.

A patched Southern Pacific AC4400CW leads two Union Pacific units and a train of empty coal hoppers west through Glenwood Canyon near Glenwood Springs, CO on October 4, 2015.

An eastbound California Zephyr passes a hi-rail truck as it apporaches the depot in Glenwood Springs, CO on October 3, 2015.

Amtrak's California Zephyr continues its journey west along the Colorado River after departing Glenwood Springs, CO on October 3, 2015.

A pair of EMD locomotives lead a train of empty hoppers towards the mines at Somerset, CO on August 16, 2015.

The view from the cab of Leadville, Colorado & Southern engine 1918 as it begins its journey down the mountain with the afternoon train in Leadville, CO on August 1, 2015.

The view from the pilot of Leadville, Colorado & Southern engine 1918 as it begins its journey down the mountain with the afternoon train in Leadville, CO on August 1, 2015.

Georgetown Loop Railroad engine number 130 leads the last train of the day downgrade across the Devil's Gate High Bridge on a chilly May 16, 2015 in Georgetown, CO.

A lashup of seven locomotives lead an eastbound manifest freight train into Glenwood Canyon near Glenwood Springs, CO on April 6, 2015.

An eastbound manifest freight train cruises through as morning light rakes across the rail yard in Laramie, WY on March 30, 2015.

The buildings of downtown Laramie, WY bask in the afternoon light as an eastbound manifest freight train rolls through on March 29, 2015.

An eastbound intermodal train blasts smoke into the air as it gets under way after waiting for a westbound train to pass in Laramie, WY on March 29, 2015.