A critical three-mile stretch of Highway 101 in California's remote Del Norte County is slowly sliding into the Pacific Ocean. Known ominously as Last Chance Grade, this fog-shrouded roadway clings to eroding cliffs between ancient redwood forests and the sea.
For decades, residents have pleaded for a permanent solution, and now the California Department of Transportation (Caltrans) is pursuing a $2.5 billion tunnel to bypass the unstable area.
The proposed 1.1-mile tunnel, which would be the longest highway tunnel in California, recently achieved a major milestone. In late May, state officials issued the final environmental impact report, a 712-page, $55 million study that followed more than a decade of public outreach and coordination with government agencies, Indigenous tribes, businesses, and environmental groups.
“It’s a proud moment,” said Jaime Matteoli, the Last Chance Grade project manager for Caltrans. “It’s a huge quality of life issue for people, feeling safe on that road.
It’s universally recognized that this project is needed.”
Highway 101 is the only viable route linking Crescent City, a tsunami-prone town of 6,000 people, with neighboring Humboldt County and the rest of California. When Last Chance Grade closes due to landslides, the only alternative route between Crescent City and the small town of Klamath 20 miles south—aside from steep, unpaved logging roads—is a circuitous 449-mile, eight-hour detour through Redding and Southern Oregon.
Del Norte County Supervisor Valerie Starkey previously told the Los Angeles Times that many Klamath children attend school in Crescent City and rely on the campus’s free meals. When rocks and mud buried Last Chance Grade in early 2021, school employees hauled lunches to the base of the landslide and handed them to Caltrans workers to take to kids on the other side.
Klamath residents also travel to the small hospital in Crescent City, while Crescent City residents use the road to access specialized medical care, including chemotherapy, more than 80 miles south in Humboldt County.
Engineers always knew the cliffs were unstable. Last Chance Grade was first built as a wagon trail through the dense redwood forest in 1894.
It was constructed in its current alignment in the 1930s, but before the work began, an engineer noted that it would be expensive to maintain because of constant land movement. During construction, many slipouts and slides delayed work, according to a 2015 project feasibility study.
The warped, cracked roadway now sits atop four active landslides. It was reduced to one-way traffic for nine years straight, reopening in October 2023, only to be repeatedly reduced since then.
Portions of the highway have shifted 40 feet horizontally and 30 feet vertically since the 1930s, with movement accelerating over the last decade—some sections now slip several feet a year toward the Pacific. Crews have built more than two dozen retaining walls to prop up the roadway, but those too have shifted, cracked, and broken.
In 1972, Last Chance Grade crumbled in the predawn darkness, and a married couple died after their Ford sedan plunged over the cliff.
The proposed underground tunnel, east of the existing highway, would bypass the most unstable areas. At 6,000 feet, it would become the longest highway tunnel in California, far surpassing the 4,233-foot Wawona Tunnel in Yosemite National Park.
However, tunnel construction would result in the loss of 16 old-growth redwood trees wider than 4 feet, along with other trees, according to the environmental impact report.
Caltrans is expected to ask the California Transportation Commission for $225 million later this summer to fund the tunnel’s design phase, which involves international experts in tunnel design and construction in seismically active zones. Matteoli said the project is on track to begin construction by about 2031, with the tunnel potentially opening by 2038.
Locals have expressed frustration over the long timeline but acknowledged that at least there is finally a plan.