Skip to main content

California State Route 1 Tom Lantos Tunnels/Old California State Route 1 Devil's Slide

By

No weekend in the Bay Area is really complete in my opinion without a good hike.  That being the case after completing Interstate 380 and driving part of California State Route 82 on the historic alignment of US 101 I made my way south along the coast on CA 1 towards Half Moon Bay.  My destination was the Devil's Slide Trailhead just south of the Tom Lantos Tunnels.

The Devil's Slide is the second alignment of CA 1 between Pacifica and Montara in San Mateo County while the Tom Lantos Tunnels are the third alignment.  .The original alignment of CA 1 in 1934 prior to the Devil's Slide between Pacifica and Montara was over Pedro Mountain Road.  Pedro Mountain Road alignment was adopted into Legislative Route Number 56 by 1933 according to CAhighways.org.  The alignment over Pedro Mountain Road and Higgins Way are very apparent on the 1935 California Division of Highways Map of San Mateo County. 

1935 California Divisions of Highway Map of San Mateo County

The Devil's Slide refers to a promontory region between Pacifica and Half Moon Bay which is part of the Montara Mountain sub-range of the Santa Cruz Mountains.  Devil's Slide in particular has natural slopes approaching 50% in places which makes the area particularly landslide prone.  Most historic transportation access prior to the 20th Century sought to avoid Devil's Slide and it wasn't until 1905 when the Ocean Shore Railway started building a line through area.  The 1906 San Francisco Earthquake destroyed much of the tracks laid at Devil's Slide but the Ocean Shore Railway eventually opened in 1908.  The goal of the Ocean Shore Railway was to create a 73 mile line between San Francisco and Santa Cruz but the northern segment never made it past Half Moon Bay before it shuttered in 1920.

In 1935 construction of a new alignment of CA 1 began at Devil's Slide and was completed by late 1937.  The Devil's Slide section of CA 1 was one of the historically most infamous along the entire highway with the first major closure coming in 1940 due to a rock slide.  The Devil's Slide area of CA 1 closed due to slides for 2 years in 1995 and had a 6 month closure in 2006 due to an eroding road deck.  Eventually CA 1 was realigned through the Tom Lantos Tunnels which were under construction from 2005 to 2013.  Both tunnels are about 4,000 in length and carry on direction of highway travel.

In 2014 the former grade of CA 1 was converted to the 1.3 mile Devil's Slide Trail which has dual trailheads at both ends of the Tom Lantos Tunnels.  More specific information regarding the Devil's Slide Trail can be found at visithalfmoonbay.org.

halfmoonbay.org on the Devil's Slide Trail

My hike was more of a trail run given the Devil's Slide is still a paved roadway.  I started actually past of the southern Devil's Slide trailhead facing the southern mouth of the Tom Lantos Tunnels.


From the Tom Lantos Tunnels the Devil's Slide Bunker can be seen to the south.  Said Bunker is actually a World War II observation station that was abandoned by 1949.  The land around the bunker apparently was stripped during a failed construction project in the 1970s.


My run began headed northward to the actual Devil's Slide trailhead over the former CA 1 right-of-way.




The Devil's Slide Trail traverses several steep road cuts before emerging out onto a wide bluff.




Along the coastal bluff the grade of the Devil's Slide Trail begins to rise steadily before coming to an observation area.







The Devil's Slide trail ends at the north parking lot trailhead which overlooks the bridges leading to the northern mouth of the Tom Lantos Tunnels.




Suffice to say the run back south on the Devil's Slide trail had some pretty scenic views from the relatively high grades.













The Devil's Slide Region was briefly covered on a prior blog containing the entire section of CA 1 between I-280 near San Francisco south to CA 17 in Santa Cruz.

November Bay Area Trip Part 7; California State Route 1 from I-280 south to CA 1780
Labels:

Comments

Post a Comment

Popular posts from this blog

Did Caltrans just kill the G26 cutout US Route shields?

By
The US Route System was formally created by the American Association of State Highway Officials during November 1926.  Through the history of the system the only state to which has elected to maintain cutout US Route shields has been California.  The G26 series cutout US Route shields have become a favorite in the road enthusiast hobby and are generally considered to be much more visually pleasing than the standard Federal Highway Administration variant.  However, the G26 shield series appears to have been killed off on January 18, 2026, when Caltrans updated their Manual of Uniform Traffic Control Devices.  This blog will examine the history of the US Route shield specifications in California and what is happening with the 2026 changes.  The blog cover photo is facing towards the terminus of California State Route 136 and at a G26-2 specification US Route 395 shield.  In the background Mount Whitney can be seen in the Sierra Nevada range.   ...
2 comments
Read more

May 2023 Ontario Trip (Part 3 of 3)

By
  Over the years, I have made plenty of trips to Ontario, crisscrossing the southern, central and eastern parts of the province. Living in Upstate New York, it's pretty easy to visit our neighbor to the north, or is that our neighbor to the west? Ottawa is one of my favorite cities to visit anywhere in the world, plus I've discovered the charm of Kingston, the waterfalls of Hamilton (which is on the same Niagara Escarpment that brings us Niagara Falls), the sheer beauty of the Bruce Peninsula, and more. But I hadn't explored much of Cottage Country. So I decided to change that, and what better time to go than over Memorial Day weekend, when the daylight is long and I have an extra day to explore. On the third and final day of my trip, I started in Huntsville and made my way through Muskoka District and Haliburton County, passing by many lakes along the way. I stopped in towns such as Dorset, Haliburton and Bancroft before making a beeline down to Belleville and then over th...
Post a Comment
Read more

Abandoned Fowler Avenue in Clovis, California

By
Originally Fowler Avenue in the city of Clovis had a brief discontinuation approaching Herndon Avenue.  Fowler Avenue traffic heading northbound was required to detour briefly onto westbound Herndon Avenue.  During 2001 this discontinuation was removed when Fowler Avenue was reconfigured to access the Sierra Freeway (California State Route 168) via an interchange.  This led to a segment of the original alignment of Fowler Avenue just south of Herndon Avenue to be abandoned.  Despite a shopping center opening over part of the original Fowler Avenue alignment in 2016 much of the abandoned roadway remains.   The history of the abandoned original alignment of Fowler Avenue in Clovis The original alignment of California State Route 168 departed downtown Clovis eastbound along Tollhouse Road.  This original alignment did not interact with Fowler Avenue at the Herndon Avenue intersection.  Fowler Avenue north of Tollhouse Road ran north to Herndon Avenue...
Post a Comment
Read more