Skip to main content

California State Route 186

California State Route 186 is a 2.128-mile State Highway located in southeastern Imperial County.  California State Route 186 begins at Interstate 8 and terminates to south near the Mexican Border via Algodones Road.   The current iteration of California State Route 186 was added to the State Highway System during 1972.  

The history of California State Route 186

The current California State Route 186 is centered around the community of Andrade.  Andrade is located on the grounds of what was once the Butterfield Overland Mail Route stage station known as Pilot Knob.  Pilot Knob can be seen on the 1873 Bancroft's Map of California in San Diego County opposite Los Algodones in the Mexican State of Sonora.  

The Alamo Canal was constructed during 1900 and 1901 which passed by the site of Pilot Knob.  The Alamo Canal originally connected from the Colorado River south to the head of the Alamo River in Mexicali Valley.  Pilot Knob was chosen as the location of the headgate (Chaffey Gate) for Alamo Canal due to the solid rock foundation.  

During 1904 a breach in the Alamo Canal four miles south of Pilot Knob in Sonora was opened.  This breach lacked headgates and was intended to bring additional waters from the Colorado River into Imperial Valley.  The unintended consequence of this action was entire Colorado River flow fully diverting into the Salton Sink numerous times during 1904-1906.  The breach Alamo Canal was closed by the Southern Pacific Railroad during February 1907 during the construction of the Inter-California Railway.  During August 1907 Imperial County would split from San Diego County.  

The Inter-California Railway was incorporated during June 1904.  When completed the Inter-California Railway began in Niland and ran south through Imperial Valley to Mexican border at Mexicali.  The Inter-California Railway passed through Los Algodones where it reentered the United States near Pilot Knob.  The Southern Pacific Railroad established a new siding facility at Pilot Knob known as Andrade.  The Inter-California Railway terminated at the Southern Pacific Railroad mainline near Andrade alongside the Alamo Canal at Araz Junction.  

The Andrade Port of Entry was established during 1909 which included a rail and road border crossing.  Andrade was named in honor of Mexican General Guillermo Andrade.  General Andrade sold land to the California Development Company to establish the Andrade town site at Pilot Knob.  Post Office service was established at Andrade during 1912.  

The Andrade Port of Entry along the Inter-California Railway can be seen in a postcard dated to 1911

The 1917 California State Automobile Association map depicts the Andrade Port of Entry.  A highway from the Andrade Port of Entry can be seen branching east towards the Arizona State line and Yuma.

The site of Andrade can be seen along the Inter-California Railway as "Cantu Andrade" on the 1935 Division of Highways Map of Imperial County.  "Cantu" is a reference to Mexican Colonel Estaban Cantu.  It is not clear when "Cantu" dropped from the Andrade community name.  

Andrade can be seen on the 1940 United State Geological Survey map of Yuma along the Inter-California Railway.  A roadway can be seen connecting Andrade to US Route 80 north of All American Canal.

The Alamo Canal was damaged by May 18, 1940, Imperial Valley Earthquake.  A $77,000 allotment from the State Emergency fund to repair Alamo Canal was featured in the July 1940 California Highways & Public Works.  Alamo Canal ultimately would be shortened back into the United States near Andrade and largely shuttered during 1942.  

The Inter-California Railway shuttered operations during 1960.  Within Mexico the trackage of the Inter-California Railway became Ferrocarril Sonora-Baja California.  The connection with the Southern Pacific Railroad was maintained but the connection at Andrade was removed.  The rail crossing at the Andrade Port of Entry was abandoned which left it only accessible by road. 

Algodones Road can be seen connecting the adopted corridor of Interstate 8 north of the All American Canal in the March/April 1965 California Highways & Public Works.  

During 1970 the Interstate 8/Algodones Road interchange was completed.  During 1972 Legislative Chapters 742 and 1216 added Algodones Road to the State Highway System as the second iteration of California State Route 186.  The original definition of the second California State Route 186 was:

"From the international boundary near Algodones to Route 8."

The original California State Route 186 existed in the San Francisco Bay area between 1965-1969 and ultimately became Interstate 380.  The second California State Route 186 can be seen along Algodones Road on the 1975 Caltrans Map.  

1990 Legislative Chapter 216 deleted the duplication route definition of California State Route 186.  During 2019 the California Transportation Commission authorized the vacation of California State Route Postmiles IMP 0.0-0.1.  This segment of California State Route 186 consisted of the portion of Algodones Road from the Andrande Port of Entry turnaround cul-de-sac to the Mexican Border.  


Popular posts from this blog

Paper Highways: The Unbuilt New Orleans Bypass (Proposed I-410)

  There are many examples around the United States of proposed freeway corridors in urban areas that never saw the light of day for one reason or another. They all fall somewhere in between the little-known and the infamous and from the mundane to the spectacular. One of the more obscure and interesting examples of such a project is the short-lived idea to construct a southern beltway for the New Orleans metropolitan area in the 1960s and 70s. Greater New Orleans and its surrounding area grew rapidly in the years after World War II, as suburban sprawl encroached on the historically rural downriver parishes around the city. In response to the development of the region’s Westbank and the emergence of communities in St. Charles and St. John the Baptist Parishes as viable suburban communities during this period, regional planners began to consider concepts for new infrastructure projects to serve this growing population.  The idea for a circular freeway around the southern perimeter of t

Hernando de Soto Bridge (Memphis, TN)

The newest of the bridges that span the lower Mississippi River at Memphis, the Hernando de Soto Bridge was completed in 1973 and carries Interstate 40 between downtown Memphis and West Memphis, AR. The bridge’s signature M-shaped superstructure makes it an instantly recognizable landmark in the city and one of the most visually unique bridges on the Mississippi River. As early as 1953, Memphis city planners recommended the construction of a second highway bridge across the Mississippi River to connect the city with West Memphis, AR. The Memphis & Arkansas Bridge had been completed only four years earlier a couple miles downriver from downtown, however it was expected that long-term growth in the metro area would warrant the construction of an additional bridge, the fourth crossing of the Mississippi River to be built at Memphis, in the not-too-distant future. Unlike the previous three Mississippi River bridges to be built the city, the location chosen for this bridge was about two

Memphis & Arkansas Bridge (Memphis, TN)

  Like the expansion of the railroads the previous century, the modernization of the country’s highway infrastructure in the early and mid 20th Century required the construction of new landmark bridges along the lower Mississippi River (and nation-wide for that matter) that would facilitate the expected growth in overall traffic demand in ensuing decades. While this new movement had been anticipated to some extent in the Memphis area with the design of the Harahan Bridge, neither it nor its neighbor the older Frisco Bridge were capable of accommodating the sharp rise in the popularity and demand of the automobile as a mode of cross-river transportation during the Great Depression. As was the case 30 years prior, the solution in the 1940s was to construct a new bridge in the same general location as its predecessors, only this time the bridge would be the first built exclusively for vehicle traffic. This bridge, the Memphis & Arkansas Bridge, was completed in 1949 and was the third