Skip to main content

Patterson Pass Road

Recently on a day trip to the San Francisco Bay Area I traversed the Diablo Range eastbound via Patterson Pass Road.


Patterson Pass Road is an approximately 13 mile roadway which starts at Mines Road in Livermore of Alameda County.  Patterson Pass Road eastward ascends over the approximately 1,600 foot namesake Patterson Pass into San Joaquin County where it ends at Interstate 580 near Tracy.  Patterson Pass Road has an infamous reputation as being a dangerous roadway due to the lengthy one-lane section and heavy rush-hour commute traffic.

Patterson Pass is one of the earliest documented European paths of travel over the Diablo Range as it was explored during the 1775-1776 Spanish Expedition led by Juan Bautista de Anza.  The 1775-1776 Spanish expedition charted out much of San Francisco Bay which led to the founding of the Presidio of San Francisco and Mission San Francisco de Asis.  Patterson Pass Road between Cross Road east to Midway Road is part of the Juan Bautista de Anza National Trail.  The Juan Bautista de Anza Trail is a 1,210 mile Auto Touring Route organized by the National Park Service which closely follows the 1775-1776 Spanish expedition from modern day Tubac, Arizona to the San Francisco Bay Area.  More information regarding the Juan Bautista de Anza National Historic Trail can be found on nps.gov and cahighways.org.

nps.gov on Juan Bautista de Anza National Historical Trail

cahighways.org on Juan Bautista de Anza National Trail in California

Patterson Pass ultimately didn't become part of the inland route of travel between the Spanish Missions on El Camino Viejo.  The route of El Camino Viejo was to the south over Corral Hollow Pass via what is now Signed County Route J2 on Tesla Road.   The earliest highway map I can find clearly showing Patterson Pass Road is a CSAA edition from 1917.

1917 CSAA State Highway Map

Patterson Pass Road can be seen on the 1935 California Division of Highways Mas of Alameda County.

1935 Alameda County Highway Map

My approach to Patterson Pass Road was from southbound Vasco Road in Livermore.  I made a left hand turn from Vasco Road onto Patterson Pass Road eastbound.



Patterson Pass Road between Vasco Road east to Greenville Road four-lanes and is directly north of Lawrence Livermore National Laboratory.



At Greenville Road the path of Patterson Pass Road drops to two lanes and exits the City of Livermore.



Patterson Pass Road east of Greenville Road to Cross Road has numerous road safety features.  Most of the traffic control measures seem to be oriented at slowing down commuter traffic.







East of Cross Road the alignment of Patterson Pass Road drops to a single lane and picks up the Juan Bautista de Anza National Historic Trail.  Patterson Pass Road is a wide single lane and quickly ascends to Patterson Past.














Patterson Pass has a wide shoulder that is worth pulling over to see as there is two wide vistas.  This view is from Patterson Pass looking west towards Livermore Valley.


The sharp descent in Patterson Pass Road eastward from the top of Patterson Pass is very dramatic to the eye.


From Patterson Pass almost all of the Altamont Pass Wind Farm can be seen.  The Altamont Pass Wind Farm was commissioned in 1981 and now consists of 4,930 wind mills which are capable of producing 576 Megawatts of electricity.


The eastward drop on Patterson Pass Road is fast and rolls through the hill side.


















As Patterson Pass Road approaches Midway Road the Altamont Pass Wind Farm sub-station can be seen at the former rail siding location Midway . Patterson Pass Road crosses under a Union Pacific rail underpass which originally part of the Western Pacific Railroad.






At Midway Road the Juan Bautista de Anza National Historic Trail splits off of Patterson Pass Road.  Patterson Pass Road expands back out to two-lanes approaching the San Joaquin County Line.



Patterson Pass Road continues eastward to I-580 as a normal two-lane roadway.





Comments

Popular posts from this blog

Interstate 210 and California State Route 210 on the Foothill Freeway

This past December I was passing through the Los Angeles Area on a weekend I took a detour onto Interstate 210 eastbound on the Foothill Freeway to California State Route 2.  I-210 and CA 210 on the Foothill Freeway essentially serve as the closest thing to a Los Angeles bypass that the L.A. Metro Area has.


I-210/CA 210 on the Foothill Freeway is an approximately 85.31 mile highway which begins at I-5 in the northern outskirts of Los Angeles and travels east to I-10 in Redlands of San Bernardino County.  I-210 exists as the 44.9 mile segment of the Foothill Freeway between I-5 and CA 57 whereas CA 210 makes up the remaining 40.41 miles east to I-10.  I-210 originally utilized CA 57 from Glendora south on the Orange Freeway to I-10.  CA 57 south to I-10 is still FHWA recognized as part of I-210 which likely won't change until California seeks approval to add CA 210 to the Interstate System.



Part 1; the history of I-210 and CA 210

I-210 was approved as a chargeable Interstate during …

California State Route 1; the Cabrillo Highway through Big Sur and the Monterey Peninsula

This past January the winter weather was mild and conditions out in the Big Sur region were especially nice.  That being the case I decided on a weekend cruise northbound on California State Route 1 via the Cabrillo Highway from CA 46 near Harmony northward through Big Sur and the Monterey Peninsula to CA 156 in Castroville.


CA 1 through the Big Sur region isn't uncharted territory for Gribblenation.  Back in 2017 when the Mud Creek Slide, Paul's Slide and the Pfeiffer Canyon Bridge collapse occurred the topic of CA 1 in Big Sur was common on this blog site.  That being the case even though the topic of CA 1 through Big Sur has been covered extensively I never really examined much of the history of the highway in the Monterey Peninsula.  Aside from the fact that I wanted to feature CA 1 through the Monterey Peninusla I'm always game for a top level scenic highway.  To that end the photos that I took on this most recent trip to CA 1 far exceed what I was taking in 2017 and …

Locans, California ghost town site

This February I stopped at the site of the abandoned railroad siding known as Locans in eastern Fresno County.


Locans was a railroad sidings of the Southern Pacific Railroad spur line known as the Stockton & Tulare Railroad.  Locans was located on what is now Temperance Avenue just south of Bulter Avenue.  The Stockton & Tulare Railroad was completed in 1887 but it doesn't appear that Locans was one of the original sidings.  Locans doesn't appear on the 1889 George F. Cram Railroad map of California but nearby Butler does.


The first reference to Locans I can find is on the 1891 Thompson Atlas of Fresno County.  A large parcel of land next to the Stockton & Tulare Railroad can be seen east of of Butler owned by F. Locan.  Locan's land holdings surround a small siding known as Minneola which was about a half mile east of where the site of Locans would eventually be plotted.


Locan's property appears again on the Stockton & Tulare Railroad between Butler an…