Pyramid Lake is a
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including control ...
formed by
Pyramid Dam on
Piru Creek in the eastern
San Emigdio Mountains, near
Castaic
Castaic () ( Chumash: ''Kaštiq''; Spanish: ''Castéc'') is an unincorporated community in the northwestern part of Los Angeles County, California. As of the 2010 census it had a population of 19,015. For statistical purposes the Census Bure ...
,
Southern California
Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most populous urban ...
. It is a part of the
West Branch 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 Mountains and valleys of Northern and Central California to Southern California. Named after Cali ...
, which is a part of the
California State Water Project. Its water is fed by the system after being pumped up from the
San Joaquin Valley
The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven ...
and through the
Tehachapi Mountains.
History
In 1843, gold was discovered near what is now Pyramid Lake, in the
Santa Feliciana Canyon
Santa Claus, also known as Father Christmas, Saint Nicholas, Saint Nick, Kris Kringle, or simply Santa, is a legendary figure originating in Western Christian culture who is said to bring children gifts during the late evening and overnigh ...
, 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, a Mexican land grant, and a handful of ranchers attempted to settle the region.
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.
Geography

Pyramid Lake is the deepest lake in the California Water Project system, built up along the steep canyon walls surrounding
Piru Creek.
The reservoir lies on the border between the
Angeles National Forest and the
Los Padres National Forest
Los Padres National Forest is a United States national forest in southern and central California. Administered by the United States Forest Service, Los Padres includes most of the mountainous land along the California coast from Ventura to Mon ...
, in the northwestern portion of
Los Angeles County
Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is th ...
. It is to the west of
Interstate 5 (I-5) south of
Tejon Pass. The former alignment of US 99 is below the waters here, replaced by I-5.

Just below the dam, Piru Creek returns to its natural state as it winds down through the
Topatopa Mountains to feed into the
Lake Piru 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 ...
to
Castaic Lake, which is the terminus of the west branch of the aqueduct.
Description
The earth and rock
dam was built by the
California Department of Water Resources and was completed in 1973. Pyramid Lake is part of the
California Aqueduct, which is part of the
California State Water Project. Outflow goes downstream to
Castaic Lake, 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, a 1,495
megawatt
The watt (symbol: W) is the unit of 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 quantify the rate of energy transfer. The watt is named after Jame ...
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 for extraction of milk
* Pumping (audio), a creative misuse of dynamic range compression
* Pumping (computer systems), the ...
hydroelectric plant located at Castaic Lake.
[CA—DWR: Pyramid Lake](_blank)
/ref> 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.
It is the deepest lake in the California Water Project system. Its name comes from the Pyramid Rock, created when a ridge was cut through in 1932 by the Ridge Route Alternate (US 99). Pyramid Rock still exists directly in front of the dam.
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 Interstate 5
Interstate 5 (I-5) is the main north–south 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 through the states of Calif ...
at Vista Del Lago Road (Exit 191).
Fishing is allowed from every location at Pyramid Lake. One can catch 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 (OEHHA) has developed a safe eating advisory for fish caught in Piru Creek based on levels of mercury or PCBs
Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act in 1979 and internationally by ...
found in local species.
See also
* List of dams and reservoirs in California
* List of lakes in California
References
External links
CA Dept. of Water Resources—DWR: Pyramid Lake Recreation website
Pyramid Lake Los Alamos campground info and reservation site
{{authority control
Reservoirs in Los Angeles County, California
California State Water Project
San Emigdio Mountains
Reservoirs in California
U.S. Route 99
Reservoirs in Southern California
Artificial lakes of the United States
1972 establishments in California