Amtrak’s westbound California Zephyr crosses South Boulder east of Pinecliffe, Colorado, on a wintery March 28, 2016. Trailing lead GE P42DC No. 81 is “phase III heritage” P40DC No. 822.

Amtrak 3 leads the California Zephyr westbound at Tunnel 29. This location is where the railroad exits South Boulder Canyon.

In the afternoon sunlight just east of Cliff Siding, Ferromex ES44AC #4691 leads a colorful consist on the BNSF Provo, UT to Denver, CO manifest on December 30th, 2017.

Eastbound coal loads roll through Pinecliffe, CO. A short bridge over South Boulder Creek and Tunnel 29 are just ahead.

As seen from California Zephyr car, the Silver Lariat, we look back at the Silver Rapids and Silver Solarium as they traverse the Colorado Rockies near Pinecliffe on the rear of Amtrak C... (more)

Amtrak #6, the eastbound California Zephyr, eases out of Tunnel 29.

Amtrak’s California Zephyr winds westbound through Tunnel 29 just east of Pinecliffe, Colorado, on the morning of May 25, 2017.

Union Pacific EMD SD70ACe No. 8550 leads a westbound coal empty through Tunnel 29 just east of Pinecliffe, Colorado, on the morning of May 13, 2017.

A westbound manifest climbs the 2% grade exiting Tunnel 29. Beyond the tunnel the train is wrapped around the tightest curve on the Moffat Road; 12 Degrees......

After meeting a westbound coal train at Cliff Siding, UP 2654 leads the eastbound MRONY out of Cliff and down to Denver.

Looking down on the canyon walls, one can see four UP units lead an empty grain train from Kaiser, California to Soloman, Kansas along South Boulder Creek in Pinecliffe, Colorado on July 9, 2017.

With clouds building over the Front Range on the morning on May 25, 2017, a westbound Union Pacific coal train rumbles through Tunnel 29 east of Pinecliffe, Colorado.

Union Pacific EMD DDA40X “Centennial” No. 6936 powers a westbound engineering passenger special curving through Pinecliffe, Colorado, on October 4, 2001.

Amtrak #5 threads thru Tunnel 29 in the Colorado Rockies. A close look will reveal a few patches of snow from a storm that dropped 20+ inches of snow on this spot, less than a week before....

A Union Pacific westbound coal empty climbs South Boulder Canyon approaching Pinecliffe, Colorado (far Right). The train has gained 2700 feet in elevation since leaving North Yard in Denver.