Caltrans Plans $2 Billion Tunnel to Save Crumbling Coastal Highway

A roadway connecting Eureka and Crescent City is a lifeline for local residents, but its future is uncertain as rock slides force repeated closures.

1 minute read

July 29, 2025, 8:00 AM PDT

By Diana Ionescu @aworkoffiction


Highway 101 winding through redwood trees with road sign for Eureka, CA partially visible in top right.

Highway 101 approaching Eureka, California. | Kirk / Adobe Stock

A $2.1 billion tunnel project aims to save Highway 101 in Northern California, where a section of the road that connects Eureka and Crescent City is at risk of falling into the ocean.

As Rachel Swan explains in the San Francisco Chronicle, the three miles of ‘Last Chance Grade’ that wind through a redwood forest have been plagued by ground tremors, winter storms, and rockslides that have forced repeated closures.

“After years of patch jobs and careful monitoring, Caltrans landed on a solution: A 6,000-foot tunnel that would bypass the landslide area, at a cost of $2.1 billion. If built, it would be the longest tunnel in state history, a bedrock lifeline for a relatively isolated place.” According to  Congressman Jared Huffman, the road carries about 6,000 vehicles each day, including freight trucks. Closing the grade creates hours-long detours.

Caltrans has set aside $275 million for design and engineering and plans to begin construction in 2030, but the project is far from fully funded. Some local officials are hoping to win federal funding, while others have proposed a toll program to help pay for the project.

Friday, July 25, 2025 in San Francisco Chronicle

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