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

Interstate 40's Tumultuous Ride Through the Pigeon River Gorge

By
In the nearly 60 years Interstate 40 has been open to traffic through the Pigeon River Gorge in the mountains of Western North Carolina, it has been troubled by frequent rockslides and damaging flooding, which has seen the over 30-mile stretch through North Carolina and Tennessee closed for months at a time. Most recently, excessive rainfall from Hurricane Helene in September 2024 saw sections of Interstate 40 wash away into a raging Pigeon River. While the physical troubles of Interstate 40 are well known, how I-40 came to be through the area is a tale of its own. Interstate 40 West through Haywood County near mile marker 10. I-40's route through the Pigeon River Gorge dates to local political squabbles in the 1940s and a state highway law written in 1921. A small note appeared in the July 28, 1945, Asheville Times. It read that the North Carolina State Highway Commission had authorized a feasibility study of a "...water-level road down [the] Pigeon River to the Tennessee l...
3 comments
Read more

Massena Center Suspension Bridge

By
The Massena Center Bridge, also known as the Holton D. Robinson Bridge, has had quite the tumultuous history. Situated on the Grasse River just east of Massena, New York in the hamlet of Massena Center, the Massena Center Bridge is a reminder of the efforts the community has made in order to connect over the river. The first and only other known bridge to be built at Massena Center was built in 1832, but that bridge was never long for this world. During the spring of 1833, the Grasse River dammed itself due to an ice dam, flooded and lifted the bridge off its foundation, destroying the bridge in the process.  The floods were frequent in the river during the spring, often backing up the river from Hogansburg and past Massena Center, but not to nearby Massena. After the first bridge disappeared, local residents had to resort to traveling seven miles west to Massena to cross the next closest bridge, and that was no easy task for a horse and buggy. However, it was many decades befo...
Post a Comment
Read more

The Dead Man's Curve of Interstate 90 and Innerbelt Freeway in Cleveland

By
"Dead Man's Curve" refers to the transition ramp Interstate 90 takes between Cleveland Memorial Shoreway onto the Innerbelt Freeway in downtown Cleveland, Ohio.  Said curve includes a sharp transition between the two freeways which is known for a high rate of accidents.  Currently the curve (not officially named) has a 35 MPH advisory speed and numerous safety features intended to mitigate crashes.  When the Interstate System was first conceived during 1956, Interstate 90 was intended to use the entirety Cleveland Memorial Shoreway and connect to the Northwest Freeway through Lakewood.  The Innerbelt Freeway was initially planned as the northernmost segment of Interstate 71.  The extension of Cleveland Memorial Shoreway west of Edgewater Park was never constructed which led to Interstate 90 being routed through the Innerbelt Freeway.   Part 1; the history of Cleveland's Innerbelt Freeway and Deadman's Curve The Federal Aid Highway Act of 1956 was signe...
Post a Comment
Read more