Pyramid Lake is a

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

formed by

Pyramid Dam Pyramid Dam is a dam on Piru Creek located in northern Los Angeles County, north of Castaic, California, Castaic and south of Gorman, California, Gorman. Its reservoir, Pyramid Lake (Los Angeles County, California), Pyramid Lake, stores water f ...

Piru Creek Piru Creek is a major stream, about long, in northern Los Angeles County and eastern Ventura County, California. It is a tributary of the Santa Clara River, the largest stream system in Southern California that is still relatively natural. Th ...

in the eastern

Topatopa Mountains The Topatopa Mountains are a mountain range in Ventura County, California, north of Ojai, Santa Paula, and Fillmore. They are part of the Transverse Ranges of Southern California. Etymology A name for the mountains was first inscribed within t ...

, near

Castaic Castaic () (Chumash: ''Kaštiq''; Spanish: ''Castéc'') is an unincorporated community and census-designated place (CDP) in northwestern Los Angeles County, California, United States. As of the 2020 census it had a population of 18,937. Ten ...

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...

. It is a part of the West Branch California Aqueduct, which is a part of the

California State Water Project The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public wat ...

. Its water is fed by the system after being pumped up from the

San Joaquin Valley The San Joaquin Valley ( ; Spanish language in California, Spanish: ''Valle de San Joaquín'') is the southern half of California's Central Valley (California), Central Valley. Famed as a major breadbasket, the San Joaquin Valley is an importa ...

and through the

Tehachapi Mountains The Tehachapi Mountains (; Kawaiisu: ''Tihachipia'', meaning "hard climb") are a mountain range in the Transverse Ranges system of California in the Western United States. The range extends for approximately in southern Kern County and northwe ...

Background

This lake was created in 1972, and completed in 1973, as a holding reservoir for the California State Water Project. The lake was named after a pyramid-shaped rock carved out by engineers building U.S. Route 99. Travelers between Los Angeles and Bakersfield christened the landmark “Pyramid Rock,” which still stands just adjacent to the dam. The earth and rock

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

was built by the

California Department of Water Resources The California Department of Water Resources (DWR) is part of the California Natural Resources Agency and is responsible for the management and regulation of the State of California's water usage. The department was created in 1956 by Governor ...

and was completed in 1973. Pyramid Lake is part of the

California Aqueduct The Governor Edmund G. Brown California Aqueduct is a system of canals, tunnels, and pipelines that conveys water collected from the Sierra Nevada and valleys of Northern and Central California to Southern California. Named after California Gov ...

, which is part of the

. Outflow goes downstream to

Castaic Lake Castaic Lake (Chumashan languages, Chumash: ''Kaštiq'') is a reservoir formed by Castaic Dam on Castaic Creek, in the Sierra Pelona Mountains of northwestern Los Angeles County, California, United States, near the town of Castaic, California, C ...

, which is the terminus of this West Branch aqueduct line. Pyramid and Castaic lakes act as the upper and lower reservoirs for the

Castaic Power Plant Castaic Power Plant, also known as the Castaic Pumped-Storage Plant, is a seven unit pumped-storage hydroelectric plant, operated by the Los Angeles Department of Water and Power, which provides peak load power from the falling water on the West ...

, a 1,495

megawatt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

pumped storage Pumping may refer to: * The operation of a pump, for moving a liquid from one location to another **The use of a breast pump A breast pump is a mechanical device that Lactation, lactating women use to milking, extract milk from their breasts. They ...

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

plant located at Castaic Lake. The plant generates electricity from the water that flows down from Pyramid Lake to Castaic Lake, and can store energy by pumping water in the reverse direction when desired. Its name comes from the Pyramid Rock, created when a ridge was cut through in 1932 by the

Ridge Route The Ridge Route, officially the Castaic–Tejon Route and colloquially known as the Grapevine, was a two-lane highway between Los Angeles County and Kern County, California. Opened in 1915 and paved with concrete between 1917 and 1921, the ro ...

Alternate (US 99). Pyramid Rock still exists directly in front of the dam. In 1843, gold was discovered near what is now Pyramid Lake, in the

Santa Feliciana Canyon Santa Claus (also known as Saint Nicholas, Saint Nick, Father Christmas, Kris Kringle or Santa) is a legendary figure originating in Western Christianity, Western Christian culture who is said to Christmas gift-bringer, bring gifts during the ...

, just south of what is now Pyramid Dam. The small find failed to trigger a rush to the mountainous countryside. Only Francisco Lopes, owner of

Rancho Temescal Rancho Temescal was a Mexican land grant in present-day Ventura County and Los Angeles County, California given in 1843 by Governor Manuel Micheltorena to Francisco Lopez and José Arellanes. The word “temescal” is Spanish for "sweat bath" ...

, a Mexican land grant, and a handful of ranchers attempted to settle the region.

Geography

Pyramid Lake is built up along the steep canyon walls surrounding

. The reservoir lies on the border between the

Angeles National Forest The Angeles National Forest (ANF) of the United States Forest Service is located in the San Gabriel Mountains and Sierra Pelona Mountains, primarily within Los Angeles County in Southern California. The ANF manages a majority of the San Gabri ...

and the

Los Padres National Forest Los Padres National Forest is a United States national forest in Southern California, southern and central California. Administered by the United States Forest Service, Los Padres includes most of the mountainous land along the California coast ...

, in the northwestern portion of

Los Angeles County Los Angeles County, officially the County of Los Angeles and sometimes abbreviated as LA County, is the most populous county in the United States, with 9,663,345 residents estimated in 2023. Its population is greater than that of 40 individua ...

. It is to the west of

Interstate 5 Interstate 5 (I-5) is the main north–south Interstate Highway System, Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific coast of the contiguous U.S. from Mexico to Canada. It travels thro ...

(I-5) south of

Tejon Pass The Tejon Pass , previously known as ''Portezuelo de Cortes'', ''Portezuela de Castac'', and Fort Tejon Pass is a mountain pass between the southwest end of the Tehachapi Mountains and northeastern San Emigdio Mountains, linking Southern Calif ...

. The former alignment of US 99 is below the waters here, replaced by I-5. The lake also lies between the

Sierra Pelona The Sierra Pelona, also known as the Sierra Pelona Ridge or the Sierra Pelona Mountains and originally known as the Liebre Mountains, is a mountain ridge in the Transverse Ranges in Southern California. Located in northwest Los Angeles County, t ...

and the

. Just below the dam, Piru Creek returns to its natural state as it winds down through the

to feed into the

Lake Piru Lake Piru () is a reservoir located in Los Padres National Forest and Topatopa Mountains of Ventura County, California, created by the construction in of the Santa Felicia Dam on Piru Creek, which is a tributary of the Santa Clara River. ...

reservoir and later the Santa Clara River. Water from Pyramid Lake continues through the

Angeles Tunnel The Angeles Tunnel is a , water tunnel located in the Sierra Pelona Mountains in Los Angeles County, California, about north of Los Angeles."Angeles Tunnel", U.S. Geological Survey.''Pyramid Lake'' 2000, p. 1.American Society 1970, p. 131. It w ...

, which is the terminus of the west branch of the aqueduct.

Recreation

Pyramid Lake offers boating, fishing, jet skiing, and picnic areas (including 5 unique sites that are accessible only by boat), and courtesy docks. Vista del Lago Visitors Center overlooks the lake. Access is from exiting

at Vista Del Lago Road (Exit 191). Fishing is allowed from every location at Pyramid Lake. This includes fish such as large mouth bass, small mouth bass, striped bass, blue gill, crappie, and some trout. The

California Office of Environmental Health Hazard Assessment The Office of Environmental Health Hazard Assessment, commonly referred to as OEHHA (pronounced oh-EEE-ha), is a specialized department within the cabinet-level California Environmental Protection Agency (CalEPA) with responsibility for evaluati ...

(OEHHA) has developed a safe eating advisory for fish caught in Piru Creek based on levels of mercury or

PCBs Polychlorinated biphenyls (PCBs) are organochlorine compounds with the formula C12 H10−''x'' Cl''x''; they were once widely used in the manufacture of carbonless copy paper, as heat transfer fluids, and as dielectric and coolant fluids f ...

found in local species. Access to the lake was temporarily closed in June 2024 due to the impacts of the

Post Fire The Post Fire was a large wildfire that burned southwest of Gorman and Lebec along Interstate 5 in Los Angeles County, California in the United States. Igniting on Saturday, June 15, 2024, at Ralph's Ranch and Gorman Post Road alongside Inter ...

Gallery

File:PyramidLkAngelesNatlFor.JPG , Pyramid Lake earthworks. File:Pyramid Lake seen from the air, Pacific Ocean in the distance.jpg, Pyramid Lake seen from the air with the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

in the distance. File:Pyramid Lake California.jpg , Pyramid Lake and

San Emigdio Mountains The San Emigdio Mountains are a part of the Transverse Ranges in Southern California, extending from Interstate 5 at Lebec and Gorman on the east to Highway 33–166 on the west. They link the Tehachapis and Temblor Range and form the southe ...

. File:Pyramid Lake, Ca. View South towards dam from boat, Oct 2010.jpg , View south towards

from boat.

References

External links