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Devil’s Slide/Tom Lantos Tunnel
Big Sur, California

California State Route 1 construction in the Devil’s Slide area began in 1935 replacing a steep narrow winding road.  A landslide in 1940 and another in 1995 forced multi-year closures.  In 2006, large cracks indicated imminent failure and the road was closed for five months and a plan was hatched to replace the unstable roadway.

In 2013, the new Tom Lantos Tunnels were opened to traffic and the old roadway was converted into a trail.  During the course of the investigation and construction for the tunnel, Geocon provided groundwater studies and performed air monitoring within the tunnels under on-call contracts with Caltrans District 4.

Interesting Fact: Most of the rock at the slide area are Paleocene (56 to 66 million years ago) turbidites (sediments carried by dense turbid (loaded with sediment) currents within clearer water.)



Environmental Services

Geocon Leader
Rick Day, CEG, CHG

Other Natural Hazards Projects
RCTD Murrieta Rock Fall Study
Murrieta, California
Town & Country Hotel
San Diego, California
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