Amtrak’s westbound California Zephyr is about to plunge into Tunnel 42 just east of Radium, Colorado, on June 24, 2024.

Powered by a pair of leased Union Pacific EMD SD70Ms, Rocky Mountaineer’s “Rockies to the Red Rocks” Colorado and Utah excursion train follows the Colorado River moments after exiting 463-fo... (more)

Amtrak train 6, the eastbound California Zephyr, passes through 463-foot Tunnel 42 as it follows the Colorado River just east of Radium, Colorado, on the afternoon of June 19, 2023.

Amtrak’s California Zephyr passes the site of Tunnel 41, removed many years ago by Rio Grande, in Little Gore Canyon approaching Radium, Colorado, on the afternoon of September 19, 2023.

A westbound Union Pacific unit oil train approaches Radium, Colorado, on September 19, 2023. In the background, the lone rear DPU unit can be seen, still rolling through Little Gore Canyon.

A westbound BNSF freight has just exited Little Gore Canyon and follows the Colorado River toward Radium, Colorado, on September 19, 2023.

A partly cloudy, moonless night reveals an eastbound Union Pacific oil train following the Colorado River into Little Gore Canyon on September 18, 2023. The lead locomotive headlights illuminate t... (more)

Amtrak’s westbound California Zephyr has just exited Little Gore Canyon and is approaching Radium, Colorado, on the afternoon of September 19, 2023.

An eastbound BNSF manifest freight follows the Colorado River through Little Gore Canyon just east of Radium, Colorado, on June 6, 2013.

Rocky Mountaineer’s “Rockies to the Red Rocks” Colorado and Utah excursion train exits 463-foot Tunnel 42 as it follows the Colorado River just east of Radium, Colorado, on the afternoon of ... (more)

Some Colorado River rafters enjoy a shoreline lunch as Amtrak’s westbound California Zephyr curves overhead while negotiating Little Gore Canyon east of Radium, Colorado, on June 20, 2023.

Union Pacific GE ES44AC No. 7444 and older AC4400CW No. 6399 power an eastbound track inspection train east out of Radium, Colorado, and are about to check out the rails through Little Gore Canyon... (more)

At 6:27 a.m. on June 20, 2023, an eastbound BNSF manifest freight curves through Radium, Colorado, utilizing trackage rights on Union Pacific’s Moffat Tunnel Subdivision. In the foreground along... (more)

Amtrak’s California Zephyr has just passed through 463-foot Tunnel 42 as it follows the Colorado River just east of Radium, Colorado, on the afternoon of June 19, 2023.

Amtrak train 5, the westbound California Zephyr, rolls along the Colorado River as it exits Little Gore Canyon between Azure and Radium, Colorado, on September 16, 2021.