Amtrak engine #170 (P42DC) heads into Tunnel 13 as runs eastward on the Moffat Tunnel Sub.

The California Zephyr runs through Tunnel #12 in South Draw, Colorado, pulling a private car on its way to Denver's Union Station.

Amtrak engine #170 (P42DC) leads the California Zephyr at sunrise through Fort Morgan, Colorado.

The evening California Zephyr #6 train runs through the tunnels at South Draw, Colorado on the Moffat Tunnel Sub.

The splendor of South Draw, Colorado under sunny skies are experienced by the passengers and crew of the California Zephyr as it runs through Tunnel 14 and heads towards Tunnel 13 on the Moffat Tu... (more)

The California Zephyr runs through South Draw as it heads east on the Moffat Tunnel Sub.

Amtrak engine #170 (P42DC) leads the California Zephyr through Fort Morgan, Colorado on the Brush Sub at sunrise.

Daily afternoon rain showers have greened-up Blue Mountain as the California Zephyr heads into Coal Creek Canyon on the Moffat Tunnel Sub.

Amtrak 89 heads down the South End Sub on a hot afternoon.

Amtrak engine #170 (P42DC) kicks up the snow as it runs the California Zephyr through Rocky, Colorado.

The blue wave pattern of the Amtrak P42DC looks great in the bright sun and the fresh snow. Here the California Zephyr splits the signals at West Tonville as it heads to Denver on the Brush Sub. ... (more)

The California Zephyr rounds the corner at Pinecliffe, Colorado as it heads higher into the Colorado Rocky Mountains on the Moffat Tunnel Sub.

With snowstorm clouds brewing to the north, the California Zephyr runs through Coal Creek Canyon and climbs up to Tunnel #1 at Plainview, Colorado.

The California Zephyr has busted through a snow drift at Big Ten Curve and now gets ready to enter Coal Creek Canyon, Colorado after rounding Blue Mountain.

Half way between Crescent, Colorado and the Moffat Tunnel Portal is Pinecliffe, offering a tunnel (29) and a great view of South Boulder Creek.