San Joaquin Hills
Encyclopedia
The San Joaquin Hills are a set of low hills in coastal Orange County, California
. They extend in a northwest-southeast direction, starting in the northwest in Newport Beach
at the southern edge of the Los Angeles Basin
, and extending southeast to San Juan Capistrano
.
French Hill in Turtle Rock
, Irvine
;
Signal Peak and Pelican Hill, both of which are near the Newport Coast
neighborhood of Newport Beach;
Temple Hill in Laguna Beach
, more commonly known as "Top of the World" after the neighborhood situated on its peak;
and Niguel Hill in Laguna Niguel
.
, lies eight miles below the hills. Scientists have suggested that the San Joaquin Hills have been formed by uplift from this fault.
The main ridge of the San Joaquin Hills runs southeast from the Newport Bay
area, attaining its maximum height of roughly 1000 feet (304.8 m) in the Laguna Beach
area. Many of the high ridges exceed 600 to 800 ft (182.9 to 243.8 m) in height. The hills stretch over a distance of about 16 miles (25.7 km) and can be up to 3 to 4 mi (4.8 to 6.4 ) broad. In many places, the San Joaquin Hills drop directly into the Pacific Ocean, creating the steep sea cliffs that characterize the region. Streams that originate on the west slope of the range include Buck Gully, Los Trancos Creek, Muddy Creek, El Moro Creek, Emerald Creek, Prima Deshecha Cañada, Segunda Deshecha Cañada, and Christianitos Canyon. The east side is drained by Bonita Creek, Sand Canyon Wash
, San Joaquin Wash, and La Cañada Wash. Cities bordering the range include Newport Beach, Irvine
, Laguna Hills
, Aliso Viejo
, Laguna Beach, Laguna Niguel
, Dana Point
, San Juan Capistrano, and San Clemente
.
Because of erosion phenomena during the previous Ice Age
, the San Joaquin Hills are not one continuous mountain range, but instead are bisected by numerous water gap
s cut by rivers flowing southwest from the Santa Ana Mountains
. In the north, Newport Bay was formed by the Santa Ana River
switching its course to the south, cutting across the northern part of the range. Laguna Canyon
was formed by San Diego Creek
, but eventually the larger creek changed course and left a wind gap
through the hills. The largest canyon by far is Aliso Canyon
, cut by Aliso Creek. Further south, the hills dissipate into smaller ridges and are bisected by the canyon of Salt Creek. The southern extent of the hills are cut by San Juan Creek
.
and California chaparral and woodlands
ecoregion
s, largely coastal sage scrub
, but other habitat types include grassland
s, oak woodlands
, wetland
s, and riparian habitat
s along several streams.
In past ages the land that is now the San Joaquin Hills lay under the ocean: construction for the San Joaquin Hills Toll Road unearthed a number of artifacts and more than 40,000 fossils, up to 35 million years old, including 5-million-year-old fossilized whales.
, owned by Jose Andres Sepulveda
. Formed in 1842 by the merger of two smaller ranches, this ranch included the northern part of the hills and likely had Laguna Canyon as its southeastern boundary. Rancho San Joaquin later became part of the Irvine Ranch
.
The San Joaquin Hills blind thrust may be the source of the earliest recorded earthquake
in California, a large earthquake felt in what is now northern Orange County on July 28, 1769 by Gaspar de Portolà
.
San Joaquin Hills, Newport Beach, California, a former census-designated place
annexed to the city of Newport Beach
, and San Joaquin Hills, Laguna Niguel, California, a master-planned community located in the city of Laguna Niguel
. Other neighborhoods set in and named after hills in this range include University Hills
and Turtle Rock
in Irvine
.
State Route 73
, also called the San Joaquin Hills Toll Road, extends through the length of the hills from Newport Beach to San Juan Capistrano. State Route 133
crosses the hills through Laguna Canyon in Laguna Beach, and they are also crossed in several other places by less major roads.
Orange County, California
Orange County is a county in the U.S. state of California. Its county seat is Santa Ana. As of the 2010 census, its population was 3,010,232, up from 2,846,293 at the 2000 census, making it the third most populous county in California, behind Los Angeles County and San Diego County...
. They extend in a northwest-southeast direction, starting in the northwest in Newport Beach
Newport Beach, California
Newport Beach, incorporated in 1906, is a city in Orange County, California, south of downtown Santa Ana. The population was 85,186 at the 2010 census.The city's median family income and property values consistently place high in national rankings...
at the southern edge of the Los Angeles Basin
Los Angeles Basin
The Los Angeles Basin is the coastal sediment-filled plain located between the Peninsular and Transverse ranges in southern California in the United States containing the central part of the city of Los Angeles as well as its southern and southeastern suburbs...
, and extending southeast to San Juan Capistrano
San Juan Capistrano, California
San Juan Capistrano is a city in southern Orange County, California, located approximately southeast of Downtown Santa Ana. The current OMB metropolitan designation for San Juan Capistrano and the Orange County Area is “Santa Ana-Anaheim-Irvine, CA.” The population was 34,593 at the 2010 census,...
.
Geography and habitats
Named summits in the San Joaquin Hills include (from north to south)French Hill in Turtle Rock
Turtle Rock, Irvine, California
Turtle Rock is a neighborhood in the south part of Irvine, Orange County, California near Concordia University, Irvine and the University of California, Irvine. It is bounded to the north by University Drive and Mason Regional Park, to the east by the Strawberry Farms Golf Club and Ridgeline Drive,...
, Irvine
Irvine, California
Irvine is a suburban incorporated city in Orange County, California, United States. It is a planned city, mainly developed by the Irvine Company since the 1960s. Formally incorporated on December 28, 1971, the city has a population of 212,375 as of the 2010 census. However, the California...
;
Signal Peak and Pelican Hill, both of which are near the Newport Coast
Newport Coast, Newport Beach, California
Newport Coast was a census-designated place until 2001, in Orange County, California, United States. The population was 9,741 at the 2010 Census. The master-planned community was developed by the Irvine Company. Newport Coast was annexed into Newport Beach, California in 2001.Newport Coast is an...
neighborhood of Newport Beach;
Temple Hill in Laguna Beach
Laguna Beach, California
Laguna Beach is a seaside resort city and artist community located in southern Orange County, California, United States, approximately southwest of the county seat of Santa Ana...
, more commonly known as "Top of the World" after the neighborhood situated on its peak;
and Niguel Hill in Laguna Niguel
Laguna Niguel, California
Laguna Niguel is an affluent city located in southern Orange County, California. The name "Laguna Niguel" is derived from the Spanish word "Laguna" which means lagoon, and the word "Nigueli" which was the name of a Juaneño Indian village that was once located on Aliso Creek. The population was...
.
Geology
A fault line, the San Joaquin Hills blind thrustThrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...
, lies eight miles below the hills. Scientists have suggested that the San Joaquin Hills have been formed by uplift from this fault.
The main ridge of the San Joaquin Hills runs southeast from the Newport Bay
Newport Bay
Newport Bay may refer to:*Disney's Newport Bay Club, a hotel situated at the Disneyland Paris*Newport Bay , an arm of Chincoteague Bay between the mainland of Worcester County, Maryland and Sinepuxent Neck...
area, attaining its maximum height of roughly 1000 feet (304.8 m) in the Laguna Beach
Laguna Beach, California
Laguna Beach is a seaside resort city and artist community located in southern Orange County, California, United States, approximately southwest of the county seat of Santa Ana...
area. Many of the high ridges exceed 600 to 800 ft (182.9 to 243.8 m) in height. The hills stretch over a distance of about 16 miles (25.7 km) and can be up to 3 to 4 mi (4.8 to 6.4 ) broad. In many places, the San Joaquin Hills drop directly into the Pacific Ocean, creating the steep sea cliffs that characterize the region. Streams that originate on the west slope of the range include Buck Gully, Los Trancos Creek, Muddy Creek, El Moro Creek, Emerald Creek, Prima Deshecha Cañada, Segunda Deshecha Cañada, and Christianitos Canyon. The east side is drained by Bonita Creek, Sand Canyon Wash
Sand Canyon Wash
Sand Canyon Wash is an approximately tributary of San Diego Creek in the U.S. state of California. Its headwaters rise in the northern San Joaquin Hills as two streams, Shady Canyon Creek and Bommer Canyon Creek, then northwest into Sand Canyon Reservoir, formed by a dam across Strawberry Valley...
, San Joaquin Wash, and La Cañada Wash. Cities bordering the range include Newport Beach, Irvine
Irvine, California
Irvine is a suburban incorporated city in Orange County, California, United States. It is a planned city, mainly developed by the Irvine Company since the 1960s. Formally incorporated on December 28, 1971, the city has a population of 212,375 as of the 2010 census. However, the California...
, Laguna Hills
Laguna Hills, California
Laguna Hills is a city located in southern Orange County, California, United States. Its name refers to its proximity to Laguna Canyon and the much older Laguna Beach. Other newer cities nearby—Laguna Niguel and Laguna Woods—are similarly named.-Geography:...
, Aliso Viejo
Aliso Viejo, California
Aliso Viejo is a city in Orange County, California. It had a population of 47,823 as of the 2010 census, up from 40,166 as of the 2000 census. It became Orange County's 34th city on July 1, 2001, the only city in the county to incorporate since 2000...
, Laguna Beach, Laguna Niguel
Laguna Niguel, California
Laguna Niguel is an affluent city located in southern Orange County, California. The name "Laguna Niguel" is derived from the Spanish word "Laguna" which means lagoon, and the word "Nigueli" which was the name of a Juaneño Indian village that was once located on Aliso Creek. The population was...
, Dana Point
Dana Point, California
-Climate:Dana Point enjoys a mild climate where temperatures tend to average around the 60's. The warmest month of the year is August with an average temperature of 79 degrees Fahrenheit. The coldest month is December with an average minimum temperature of 44 degrees Fahrenheit.-2010:The 2010...
, San Juan Capistrano, and San Clemente
San Clemente, California
San Clemente is a city in Orange County, California. The population was 63,522 at the 2010 census. Located on the California Coast, midway between Los Angeles and San Diego at the southern tip of the county, it is known for its ocean, hill, and mountain views, a pleasant climate and its Spanish...
.
Because of erosion phenomena during the previous Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
, the San Joaquin Hills are not one continuous mountain range, but instead are bisected by numerous water gap
Water gap
A water gap is an opening or notch which flowing water has carved through a mountain range. Water gaps often offer a practical route for road and rail transport to cross mountain ridges.- Geology :...
s cut by rivers flowing southwest from the Santa Ana Mountains
Santa Ana Mountains
The Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately 36 mi southeast of the Los Angeles Basin largely along the border between Orange and Riverside counties.- Geography :The range starts in the...
. In the north, Newport Bay was formed by the Santa Ana River
Santa Ana River
The Santa Ana River is the largest river of Southern California in the United States. Its drainage basin spans four counties. It rises in the San Bernardino Mountains and flows past the cities of San Bernardino and Riverside, before cutting through the northern tip of the Santa Ana Mountains and...
switching its course to the south, cutting across the northern part of the range. Laguna Canyon
Laguna Canyon
Laguna Canyon is a canyon, formerly a water gap, that cuts through the San Joaquin Hills in southern Orange County in the U.S. state of California, directly west of the city of Irvine...
was formed by San Diego Creek
San Diego Creek
San Diego Creek is a waterway flowing into Upper Newport Bay in central Orange County in the U.S. state of California. Its basin covers in parts of eight cities, including Irvine, Tustin, and Costa Mesa. The major tributary of the northeast-flowing stream is Peters Canyon Wash, which joins a few...
, but eventually the larger creek changed course and left a wind gap
Wind gap
A wind gap is a valley through which a waterway once flowed, but is now dry as a result of stream capture. A water gap is a similar feature, but one in which a waterway still flows...
through the hills. The largest canyon by far is Aliso Canyon
Aliso Canyon
Aliso Canyon is a canyon cut through the San Joaquin Hills by Aliso Creek. Located in Orange County in the U.S. state of California, the canyon's name derives from the Spanish word for alder....
, cut by Aliso Creek. Further south, the hills dissipate into smaller ridges and are bisected by the canyon of Salt Creek. The southern extent of the hills are cut by San Juan Creek
San Juan Creek
San Juan Creek, also called the San Juan River, is a stream in Orange County, California that consists of a catchment basin encompassing . Its mainstem rises in the Santa Ana Mountains, in the Trabuco Ranger District of the Cleveland National Forest...
.
Flora and Fauna
The native vegetation of the hills is in the California coastal sage and chaparralCalifornia coastal sage and chaparral ecoregion
The California coastal sage and chaparral, a sub-ecoregion of the California chaparral and woodlands ecoregion, is found in southwestern California and northwestern Baja California in Mexico.-Location:...
and California chaparral and woodlands
California chaparral and woodlands
The California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
ecoregion
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
s, largely coastal sage scrub
Coastal sage scrub
Coastal sage scrub is a low scrubland plant community found in the California chaparral and woodlands ecoregion of coastal California and northern Baja California. It is characterized by low-growing aromatic, and drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the...
, but other habitat types include grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
s, oak woodlands
California oak woodland
California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico...
, wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s, and riparian habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s along several streams.
In past ages the land that is now the San Joaquin Hills lay under the ocean: construction for the San Joaquin Hills Toll Road unearthed a number of artifacts and more than 40,000 fossils, up to 35 million years old, including 5-million-year-old fossilized whales.
History
The hills take their name from Rancho San JoaquinRancho San Joaquin
Rancho San Joaquin, the combined Rancho Cienega de las Ranas and Rancho Bolsa de San Joaquin, was a Mexican land grant in present day Orange County, California given to José Antonio Andres Sepúlveda...
, owned by Jose Andres Sepulveda
Francisco Xavier Sepulveda
Francisco Xavier Sepúlveda was a Mexican colonial soldier and patriarch of the prominent Spanish Mexican Sepúlveda family in the early days of Las Californias and Alta California in present day Southern California, United States...
. Formed in 1842 by the merger of two smaller ranches, this ranch included the northern part of the hills and likely had Laguna Canyon as its southeastern boundary. Rancho San Joaquin later became part of the Irvine Ranch
Irvine Company
The Irvine Company is a privately held real estate development company based in Newport Beach, Orange County, Southern California. The corporate center of the company lies in Newport Center. A large portion of its operations are centered in and around the City of Irvine, a planned city of 250,000...
.
The San Joaquin Hills blind thrust may be the source of the earliest recorded earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
in California, a large earthquake felt in what is now northern Orange County on July 28, 1769 by Gaspar de Portolà
Gaspar de Portolà
Gaspar de Portolà i Rovira was a soldier, governor of Baja and Alta California , explorer and founder of San Diego and Monterey. He was born in Os de Balaguer, province of Lleida, in Catalonia, Spain, of Catalan nobility. Don Gaspar served as a soldier in the Spanish army in Italy and Portugal...
.
Development
Two neighborhoods within the San Joaquin Hills take the name of the hills for their own:San Joaquin Hills, Newport Beach, California, a former census-designated place
Census-designated place
A census-designated place is a concentration of population identified by the United States Census Bureau for statistical purposes. CDPs are delineated for each decennial census as the statistical counterparts of incorporated places such as cities, towns and villages...
annexed to the city of Newport Beach
Newport Beach, California
Newport Beach, incorporated in 1906, is a city in Orange County, California, south of downtown Santa Ana. The population was 85,186 at the 2010 census.The city's median family income and property values consistently place high in national rankings...
, and San Joaquin Hills, Laguna Niguel, California, a master-planned community located in the city of Laguna Niguel
Laguna Niguel, California
Laguna Niguel is an affluent city located in southern Orange County, California. The name "Laguna Niguel" is derived from the Spanish word "Laguna" which means lagoon, and the word "Nigueli" which was the name of a Juaneño Indian village that was once located on Aliso Creek. The population was...
. Other neighborhoods set in and named after hills in this range include University Hills
University Hills, Irvine, California
University Hills is a community in southern Irvine, California, consisting of 940 for-sale homes and 240 rental units. Located on the campus of the University of California, Irvine, University Hills was developed by the Irvine Campus Housing Authority and built by local home builders as a place...
and Turtle Rock
Turtle Rock, Irvine, California
Turtle Rock is a neighborhood in the south part of Irvine, Orange County, California near Concordia University, Irvine and the University of California, Irvine. It is bounded to the north by University Drive and Mason Regional Park, to the east by the Strawberry Farms Golf Club and Ridgeline Drive,...
in Irvine
Irvine, California
Irvine is a suburban incorporated city in Orange County, California, United States. It is a planned city, mainly developed by the Irvine Company since the 1960s. Formally incorporated on December 28, 1971, the city has a population of 212,375 as of the 2010 census. However, the California...
.
State Route 73
California State Route 73
State Route 73 is a state highway in the U.S. state of California. The route runs from Interstate 405 to Interstate 5 through the San Joaquin Hills in Orange County. From its northern terminus, the first three miles of the highway are called the Corona del Mar Freeway; this section of highway...
, also called the San Joaquin Hills Toll Road, extends through the length of the hills from Newport Beach to San Juan Capistrano. State Route 133
California State Route 133
State Route 133 is a state highway in the U.S. state of California. It connects SR 1 in Laguna Beach through the San Joaquin Hills with several freeways in Irvine, ending at the SR 241 toll road in the latter city...
crosses the hills through Laguna Canyon in Laguna Beach, and they are also crossed in several other places by less major roads.