Tunnel 41 allows people on the California Zephyr to pass through the most treacherous part of the California trail with ease.

This includes enhancing iconic routes like the California Zephyr, which stretches from Chicago to the San Francisco Bay Area, and the Crescent, which links New York City and New Orleans.

Amtrak's 15 long-distance routes stretch as long as the 2,400 mile California Zephyr line, running from Chicago to the San Francisco area.