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

Sunshine Bridge (Donaldsonville, LA)

Located about halfway between Baton Rouge and New Orleans in southern Louisiana, the Sunshine Bridge spans the lower Mississippi River near the city of Donaldsonville as part of the longer Louisiana Highway 70 corridor, which connects Interstate 10 and Airline Highway (US 61) with US 90 in Morgan City. In the years following World War II, the only bridges across the lower Mississippi River in Louisiana were located in the area of the state’s two largest cities – Baton Rouge and New Orleans. Postwar agricultural and industrial development along the river in this region led to the planning of a series of infrastructure projects in southern Louisiana that were aimed at spurring this development and modernization of the Delta region. One of these projects was known as the Acadian Thruway and was developed in the 1950s as a toll road intended to connect greater New Orleans with Lafayette and points west while providing a high-speed bypass of the Baton Rouge metro area. The Thruway, which

Old River Lock & Control Structure (Lettsworth, LA)

  The Old River Control Structure (ORCS) and its connecting satellite facilities combine to form one of the most impressive flood control complexes in North America. Located along the west bank of the Mississippi River near the confluence with the Red River and Atchafalaya River nearby, this structure system was fundamentally made possible by the Flood Control Act of 1928 that was passed by the United States Congress in the aftermath of the Great Mississippi River Flood of 1927 however a second, less obvious motivation influenced the construction here. The Mississippi River’s channel has gradually elongated and meandered in the area over the centuries, creating new oxbows and sandbars that made navigation of the river challenging and time-consuming through the steamboat era of the 1800s. This treacherous area of the river known as “Turnbull’s Bend” was where the mouth of the Red River was located that the upriver end of the bend and the Atchafalaya River, then effectively an outflow

Natchez-Vidalia Bridge (Natchez, MS)

  Located about halfway between Baton Rouge and Vicksburg near the city of Natchez, the Natchez-Vidalia Bridge crosses the lower Mississippi River between southwest Mississippi and northeastern Louisiana at the city of Vidalia. This river crossing is a dual span, which creates an interesting visual effect that is atypical on the Mississippi River in general. Construction on the original bridge took place in the late 1930s in conjunction with a much larger parallel effort by the U.S. Army Corps of Engineers to strengthen the area’s flood protection and levee system along the Mississippi River. One of the more ambitious aspects of this plan was to relocate the city of Vidalia to a location of higher ground about one mile downriver from the original settlement. The redirection of the river through the Natchez Gorge (which necessitated the relocation of the town) and the reconstruction of the river’s levee system in the area were undertaken in the aftermath of the Great Flood of 1927, wh