Bay Area by Sentinel-2, 2019-03-11 (small version)

San Francisco Peninsula by Sentinel-2, 2019-03-11

The San Francisco Peninsula is a

peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on a ...

in the

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area G ...

that separates

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water f ...

from the

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

. On its northern tip is the

City and County of San Francisco San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...

. Its southern base is Mountain View, south of

Palo Alto Palo Alto (; Spanish for "tall stick") is a charter city in the northwestern corner of Santa Clara County, California, United States, in the San Francisco Bay Area, named after a coastal redwood tree known as El Palo Alto. The city was es ...

and north of

Sunnyvale Sunnyvale () is a city located in the Santa Clara Valley in northwest Santa Clara County in the U.S. state of California. Sunnyvale lies along the historic El Camino Real and Highway 101 and is bordered by portions of San Jose to the nort ...

and Los Altos. Most of the Peninsula is occupied by San Mateo County, between San Francisco and Santa Clara counties, and including the cities and towns of Atherton, Belmont,

Brisbane Brisbane ( ) is the capital and most populous city of the Australian state of Queensland, and the third-most populous city in Australia and Oceania, with a population of approximately 2.6 million. Brisbane lies at the centre of the South ...

, Burlingame, Colma,

Daly City Daly City () is the second most populous city in San Mateo County, California, United States, with population of 104,901 according to the 2020 census. Located in the San Francisco Bay Area, and immediately south of San Francisco (sharing its ...

, East Palo Alto, El Granada,

Foster City Foster City is a city located in San Mateo County, California. The 2020 census put the population at 33,805, an increase of more than 10% over the 2010 census figure of 30,567. Foster City is sometimes considered to be part of Silicon Valle ...

, Hillsborough, Half Moon Bay,

La Honda La Honda (Spanish for "The Sling") is a census-designated place (CDP) in southern San Mateo County, California, United States. The population was 979 at the 2020 census. It is located in the Santa Cruz Mountains between the Santa Clara Valley and ...

, Loma Mar, Los Altos, Menlo Park,

Millbrae Millbrae is a city located in northern San Mateo County, California, United States. To its northeast is San Francisco International Airport, San Bruno is on its northwest, and Burlingame on its southeast. It is bordered by San Andreas Lake ...

, Pacifica,

, Pescadero,

Portola Valley Portola Valley is a town in San Mateo County, California. Located on the San Francisco Peninsula in the Bay Area, Portola Valley is a small, wealthy community nestled on the eastern slopes of the Santa Cruz Mountains. History Portola Va ...

, Redwood City,

San Bruno San Bruno (Spanish for " St. Bruno") is a city in San Mateo County, California, United States, incorporated in 1914. The population was 43,908 at the 2020 United States Census. The city is between South San Francisco and Millbrae, adjacent to ...

, San Carlos, San Mateo,

South San Francisco South San Francisco is a city in San Mateo County, California, United States, located on the San Francisco Peninsula in the San Francisco Bay Area. The city is colloquially known as "South City". The population was 66,105 at the 2020 cens ...

, and

Woodside Woodside may refer to: Places and buildings Australia * Woodside, South Australia, a town * Woodside, Victoria, a town Canada * Woodside National Historic Site, the boyhood home of William Lyon Mackenzie King *Woodside, Nova Scotia, a neighbo ...

. Whereas the term ''peninsula'' in a geographical sense technically refers to the entire San Francisco Peninsula, in local jargon, "The Peninsula" does not include the city of San Francisco.

History

In 1795, Governor Diego de Borica gave José Darío Argüello a Spanish land grant known as

Rancho de las Pulgas Rancho de las Pulgas was a 1795 Spanish land grant in present-day San Mateo County, California to José Darío Argüello. The literal translation is "Ranch of the Fleas", probably named after a village of the local Lamchin people. The grant w ...

. This rancho was the largest grant on the peninsula consisting of . As a local geographic term, the area referred to as "the Peninsula" is distinct from that denoted by "the City", and refers to the portion south of San Francisco. The appellation may date to the period prior to 1856, when the City of San Francisco and the County of San Francisco were separate entities, the latter then coextensive with contemporary San Mateo County and San Francisco City-County. The City-County owns several disjunct properties along the whole of the Peninsula (mostly water pumping stations connected to the Hetch Hetchy Valley on which San Francisco has a permanent leasehold) – thus, most of the larger communities in San Mateo County are ''de facto'' suburbs of San Francisco, with the neighboring communities of Pacifica, Daly City, Broadmoor, Colma, South San Francisco, Half Moon Bay, San Bruno, and Brisbane being immediate suburbs. The remaining suburban area of the Peninsula is on the east side of the

Santa Cruz Mountains The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central and Northern California, United States. They form a ridge down the San Francisco Peninsula, south of San Francisco. They separate the Pacific Ocean from ...

, along

; the west and south-central portions of the Peninsula are mostly rural, unincorporated, and unorganized areas. A substantial portion of

Silicon Valley Silicon Valley is a region in Northern California that serves as a global center for high technology and innovation. Located in the southern part of the San Francisco Bay Area, it corresponds roughly to the geographical areas San Mateo Cou ...

is located on the peninsula. In Silicon Valley are the headquarters of some of the largest tech companies in the world, such as Google, Yahoo, Facebook, and Apple. Since 2010, droughts and wildfires have increased in frequency and become less seasonal and more year-round, further straining the region's

water security Water security is the focused goal of water policy and water management. A society with a high level of water security makes the most of water's benefits for humans and ecosystems and limits the risk of destructive impacts associated with water. T ...

Geography and transportation

Along the center line of the Peninsula is the northern half of the

, formed by the action of

plate tectonics Plate tectonics (from the la, label= Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of larg ...

along the

San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal) ...

. In the middle of the Peninsula along the fault is the

Crystal Springs Reservoir Crystal Springs Reservoir is a pair of artificial lakes located in the northern Santa Cruz Mountains of San Mateo County, California situated in the rift valley created by the San Andreas Fault just to the west of the cities of San Mateo and Hi ...

. Just north of the Crystal Springs reservoir is San Andreas Lake, after which the

geologic fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

was originally named. The east side of the peninsula is a densely populated and largely urban and suburban area that includes portions of Silicon Valley. It forms a commuter area between San Francisco to the north and San Jose to the south.

Roads

Interstate 80 Interstate 80 (I-80) is an east–west transcontinental freeway that crosses the United States from downtown San Francisco, California, to Teaneck, New Jersey, in the New York metropolitan area. The highway was designated in 1956 as one ...

Interstate 280 * I-380 (CA)

Interstate 380 * US 101 (CA)

U.S. Route 101 U.S. Route 101, or U.S. Highway 101 (US 101), is a north–south United States Numbered Highway that runs through the states of California, Oregon, and Washington, on the West Coast of the United States. It is also known as (The Royal Roa ...

State Route 1 * California 9

State Route 9 * California 35

State Route 35 * California 82

State Route 82 * California 84

State Route 84 * California 85

State Route 85 * California 92

State Route 92 * California 109

State Route 109 * California 114

State Route 114 * California 237

State Route 237 The bridges in the Peninsula include the Dumbarton Bridge, the

Golden Gate Bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean. The structure links the U.S. city of San Francisco, California—the northern tip of the San Francisco Pen ...

, the San Francisco - Oakland Bay Bridge, and the San Mateo-Hayward Bridge. A number of major thoroughfares run north-south: El Camino Real ( SR 82) and US 101 on the east side along the bay, Interstate 280 down the center, Skyline Boulevard ( SR 35) along the crest of the

, and SR 1 on the west along the Pacific, and SR 85 which forms the southern end of the Peninsula.

Transit

Caltrain Caltrain (reporting mark JPBX) is a California commuter rail line serving the San Francisco Peninsula and Santa Clara Valley (Silicon Valley). The southern terminus is in San Jose at Tamien station with weekday rush hour service running as fa ...

is the primary passenger rail transit in the peninsula, serving much of the eastern urbanized areas of the peninsula between Mountain View (which also connects to

VTA light rail VTA Light Rail is a light rail system in San Jose and nearby cities in Santa Clara County, California. It is operated by the Santa Clara Valley Transportation Authority, or VTA, and consists of of network comprising three main lines on stand ...

) and San Francisco's 4th and King Street stationIn addition, the peninsula has access to

Bay Area Rapid Transit Bay Area Rapid Transit (BART) is a rapid transit system serving the San Francisco Bay Area in California. BART serves 50 stations along six routes on of rapid transit lines, including a spur line in eastern Contra Costa County which u ...

(BART) northward of

, connecting San Mateo County and San Francisco to the

East Bay The East Bay is the eastern region of the San Francisco Bay Area and includes cities along the eastern shores of the San Francisco Bay and San Pablo Bay. The region has grown to include inland communities in Alameda and Contra Costa counties ...

through a route over and under

, Glen Park,

San Francisco's Mission district The Mission District (Spanish: ''Distrito de la Misión''), commonly known as The Mission (Spanish: ''La Misión''), is a neighborhood in San Francisco, California. One of the oldest neighborhoods in San Francisco, the Mission District's name is ...

, and through part of Market Street subway. Bus service is predominantly served by

SamTrans SamTrans (stylized as samTrans; officially the San Mateo County Transit District) is a public transport agency in and around San Mateo, California, in the San Francisco Bay Area. It provides bus service throughout San Mateo County and into porti ...

and the SFMTA's Muni buses, predominantly serving San Mateo and San Francisco counties respectively. In addition, southward of Palo Alto, the Santa Clara Valley Transportation Authority operates buses to other parts of Santa Clara County. Most of the peninsula's bus transit to the

and North Bay flowing through San Francisco, as neither

AC Transit AC Transit (Alameda-Contra Costa Transit District) is an Oakland-based public transit agency serving the western portions of Alameda and Contra Costa counties in the East Bay of the San Francisco Bay Area. AC Transit also operates "Transbay" r ...

nor Golden Gate Transit, the primary transit operators for the East and North Bay respectively, do not serve the peninsula south of San Francisco.

Airports

The peninsula's sole commercial airport is

San Francisco International Airport San Francisco International Airport is an international airport in an unincorporated area of San Mateo County, south of Downtown San Francisco. It has flights to points throughout North America and is a major gateway to Europe, the Middl ...

, itself connected to US 101 and BART. Access to the two other major commercial airports within the Bay Area,

Oakland Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the Bay ...

and San Jose, requires usage of BART or the VTA.

Environmental features

The San Francisco Peninsula contains a variety of habitats including

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...

, marine, oak woodland, redwood forest, coastal scrub and oak

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground ...

. There are numerous species of wildlife present, especially along the

shoreline,

San Bruno Mountain San Bruno Mountain is horst fault block mountain located in northern San Mateo County, California; with some northern slopes crossing over into southern San Francisco, it is also surrounded by San Francisco Bay and the cities of Brisbane, Colma ...

Fitzgerald Marine Reserve Fitzgerald Marine Reserve is a marine reserve in California on the Pacific Ocean, located just north of Pillar Point Harbor and Mavericks in the San Mateo County community of Moss Beach. Moss Beach is located approximately south of San Fr ...

and the

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s on the Montara Mountain block. The county is home to several endangered species including the San Francisco garter snake, the Mission blue butterfly and the

San Bruno elfin butterfly The San Bruno elfin (''Callophrys mossii bayensis'') is a U.S. federally listed endangered subspecies that inhabits rocky outcrops and cliffs in coastal scrub on the San Francisco Peninsula. It is endemic to this habitat in California. Its patch ...

, all of which are endemic to San Mateo County. The

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

California clapper rail is also found on the shores of

, in the cities of Belmont and San Mateo. A number of noteworthy parks and nature preserves are found on the San Francisco Peninsula, including: * Edgewood Park, San Mateo County * Golden Gate National Recreation Area - several units are located on the Peninsula *

Midpeninsula Regional Open Space District Formed in 1972 by voter initiative, the Midpeninsula Regional Open Space District (MROSD) is a non-enterprise special district in the San Francisco Bay Area. It has acquired and preserved a regional green belt of open space land and provides o ...

- several preserves * Shoreline Park, Mountain View, Santa Clara County

Notable structures

There are a number of well-known structures and complexes on the San Francisco Peninsula: * Bay Meadows Racecourse, San Mateo (demolished in 2008) *

Carolands Mansion Carolands Chateau is a , 4.5 floor, 98 room mansion on in Hillsborough, California. An example of American Renaissance and Beaux-Arts architecture, Beaux-Arts design, the building is a California Historical Landmark and is listed on the Nationa ...

, Hillsborough * Cow Palace, Daly City * Crocker Mansion, Hillsborough *

, west of Interstate 280 *

CuriOdyssey CuriOdyssey is a science museum and zoo for children and families where visitors can see wild animals up-close and visit interactive science exhibits. CuriOdyssey is home to nearly 100 rescued animals, most native to California, that cannot survi ...

museum, San Mateo * Dakin Building, Brisbane *

Meta Platforms Meta Platforms, Inc., (file no. 3835815) doing business as Meta and formerly named Facebook, Inc., and TheFacebook, Inc., is an American multinational technology conglomerate based in Menlo Park, California. The company owns Facebook, Insta ...

, world headquarters, Menlo Park * Filoli mansion and gardens, Woodside *

Frenchman's Tower Frenchman's Tower is a two-story red brick structure located in Santa Clara County, California, that resembles a medieval fortification. Built in 1875, the structure was listed as a California Point of Historical Interest in 1969. The structure wa ...

, Palo Alto *

Google Inc. Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. It ...

, World Headquarters, Mountain View * " The Flintstone House", east side of Interstate 280
*

Notre Dame de Namur University Notre Dame de Namur University (NDNU) is a private Catholic university in Belmont, California. It is the third oldest college in California and the first college in the state authorized to grant the baccalaureate degree to women. In 2021, the ...

, Belmont, with

Ralston Hall Ralston Hall Mansion located in Belmont, California, was the country house of William Chapman Ralston, a San Francisco businessman, a founder of the Bank of California, and a financier of the Comstock Lode. It is an opulent Italianate Villa, mo ...

Oracle An oracle is a person or agency considered to provide wise and insightful counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. As such, it is a form of divination. Description The word ...

World Headquarters, Redwood Shores (aka the "Emerald City") * Pulgas Water Temple, Woodside *

* Sanchez Adobe Park, Pacifica *

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is conside ...

campus, Palo Alto

References

External links

* {{Coord, 37, 35, 00, N, 122, 24, 04, W, source:GNIS_scale:500000, display=title Peninsulas of California Landforms of the San Francisco Bay Area Geography of San Francisco Geography of San Mateo County, California Geography of Santa Clara County, California Regions of California *