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Elkhorn Grade Road (Carrizo Plain National Monument)


Elkhorn Grade Road is an approximately six-mile dirt surfaced rural highway which originates in Carrizo Plains National Monument.  The grade begins at Elkhorn Road in San Luis Obispo County and enters Kern County where it crests at an elevation of 1,807 feet above sea level in the Temblor Range.  The remaining balance of the grade continues east/northeast to California State Routes 166 and 33 near Maricopa.

Elkhorn Grade Road was one of two roadways used by the Carrisa Chemical Company to haul freight out of Soda Lake.  The corridor appears as a prominent highway on early United States Geological Survey maps dating back to 1910.  




Part 1; the history of Elkhorn Grade Road

The Elkhorn Grade is an approximately 6-mile spur of the 40-mile-long Elkhorn Road.  Elkhorn Road begins at Soda Lake Road at the southern extent of Carrizo Plain and extends to through the namesake National Monument to 7 Mile Road in the unincorporated community of California Valley.  Much of Elkhorn Road lies in a fold (Elkhorn Valley) following the San Andreas Fault east of Soda Lake.  By contrast the Elkhorn Grade branches east from Elkhorn Road near the southern extent of the National Monument.  The grade crosses a ridge in the Temblor Range descends to California State Routes 166 and 33 near Maricopa.  


Soda Lake is one of the largest undisturbed alkali wetlands on the west coast at approximately 3,000 acres.  Soda Lake is located at the bottom of a basin in the center of Carrizo Plain which has no outlet.  Carrizo Plain (and by proxy Soda Lake) is bounded by the Caliente Range to the west and the Temblor Range to the east.  Soda Lake is often full of water during the winter and spring from mountain runoff which quickly dries as summer approaches.  Although Carrizo Plain is technically a grass land it only receives 9 inches of rain annually and closely resembles a desert climate during summer months.  The result of Soda Lake drying is a significant layer of salt deposits is left at the bottom of Carrizo Plain.

The Temblor Range is notably where the San Andreas Fault bisects the North American Plate and Pacific Plate in Carrizo Plain.  Carrizo Plain is thought to have been the epicenter of the 1857 Fort Tejon Earthquake.  The Fort Tejon Earthquake was a 7.9 magnitude temblor which has been noted to have displaced parts of the Carrizo Plain by as much as 23 feet at the base of the Temblor Range.  A larger earthquake on the San Andreas Fault between 1540 and 1630 has been noted to have caused a 40.6-foot offset in Carrizo Plain.  Carrizo Plain has previously been known as "Carisa Plain" and "Carrisa Plain" during the 19th Century onward towards the early 20th Century.  Soda Lake often is referred to as "Carrisa Lake" in historical records.

Beginning during the 1880s ranchers began to mine saline deposits from Soda Lake for use in their operations.  The 1880s also saw a small swath of large unsuccessful mining operations around Carrizo Plain.  Circa 1908 the Carrisa Chemical Company constructed a large plant which could process 600 tons of salt deposits a month.  The Carrisa Chemical Company constructed a narrow-gauge railroad during 1916-1917 which began at the northern tip of Soda Lake.  The railroad crossed Soda Lake southward and ended near the base of the Temblor Range.  Soda Lake Road and the Elkhorn Grade were used by the Carrisa Chemical Company to haul loads from the end of the railroad out of the Temblor Range. 

The Elkhorn Grade can be seen on the 1910 United States Geological Survey of Buena Vista Lake.  The corridor is shown to branch away from Elkhorn Road in San Luis Obispo County and cross the Kern County line.  Upon crossing into Kern County, the grade is shown cresting the Temblor Range at 1,807 feet above sea level before descending into Maricopa via Bitterwater creek. 


The Carrisa Chemical Company shuttered its mineral operations at Soda Lake during the 1950s and removed its railroad line.  During the 1960s much of the land in Carrizo Plain north of Soda Lake was sold due to real estate developers in the belief that the California State Water Project would build a reservoir there.  In the 1970s a final segment of Soda Lake Road near Traver Ranch was paved to reduce the amount of dust being kicked up by travelers.  

In 1988 the Bureau of Land Management, California Department of Fish & Game, and the Nature Conservancy partnered to purchase 82,000 acres of land within Carrizo Plain.  The stake holders in the purchase within Carrizo Plain organized their holdings into the Carrizo Plain Natural Area during 1996.  On January 12, 2001, President Bill Clinton signed a proclamation which established Carrizo Plain National Monument.  Carrizo Plain was one of the first in an increasing trend of new National Monuments which aren't managed by the National Park Service.



Part 2; a drive on Elkhorn Grade Road

Pictured below the paved portion of Soda Lake Road can be seen intersecting the southern end of Elkhorn Road.  Traffic wishing to access the Elkhorn Grade can reach it via a left-hand turn onto Elkhorn Road and following it to a junction approximately one mile to the east.  All photos in Part 2 were submitted by Josh Schmid and taken during April 2024. 

The eastward view from the top of the Elkhorn Grade overlooks Maricopa and much of San Joaquin Valley.  Bear Mountain can be seen on the far right in the Tehachapi Mountains.  

The descent along the Elkhorn Grade can be viewed below.  Most sources note Elkhorn Grade Road to be suitable for high clearance vehicles.  That said, there are numerous recent documented instances of travelers in low clearance vehicles making it through in dry weather.  The last half mile the Elkhorn Grade is paved approaching California State Routes 166 and 33.  


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