Electro-Motive Division SD90MAC-H demonstrator locomotive No. 8504 heads west on Union Pacific’s former Rio Grande main line at Rocky, Colorado, for some high-altitude testing on February 3, 199... (more)

A long Union Pacific train of covered hoppers negotiates the curves at Rocky, Colorado, with EMD SD70ACe No. 8933 as rear DPU on the eastbound train on June 21, 2018.

DRGW 5771 leads westbound Train #117 at Rocky, CO, Mar 11, 1979.

DRGW 3116 with the westbound Ski Train at Rock, CO, on Mar 11, 1978.

Four GE products lead a mixed freight down the 2% grade to Denver on a sunny December morning. The snow on the plow gives a hint to the conditions at higher elevations, as the sun down here, doesn... (more)

AMTK 133 leads the California Zephyr through the evergreens of Plainview, Colorado.

AMTK 133 leads the California Zephyr down the grade of Big Ten Curve.

AMTK 189 (P42DC) leads the California Zephyr past the Rocky Siding as it heads to Arvada, Colorado.

The California Zephyr, lead by AMTK 52, heads towards Big Ten Curve as a BNSF oil train that has just past through the landmark curve gets ready to head towards Denver.

Amtrak’s westbound California Zephyr climbs out of Rocky, Colorado, on July 4, 2005. Above the train in the background is the east switch of Clay siding.

Amtrak’s California Zephyr meets a westbound BNSF freight at Rocky, Colorado, on the afternoon of June 28, 2014. In the background is the city of Denver, where train 6 will be making a station a... (more)

A long Union Pacific coal train makes its way around Big Ten Curve as it drops down the 2% grade while rounding the wide 280 degree curve.

A winter wonderland greets riders of the California Zephyr as AMTK 189 (P42DC) leads the train around Big Ten Curve, which will drop the train 2% along the 280 degree curve.

The morning California Zephyr gets ready to pass a waiting BNSF oil can train which has pulled off onto a siding just after the Big Ten Curve to let the Zephyr pass.

A fresh layer of snow has blanketed the foothills and trees as Amtrak 130 leads the California Zephyr up the Moffat Tunnel line and into the Colorado Rocky Mountains.