San Francisco Peninsula

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Satellite photo of the San Francisco Bay Area. The San Francisco peninsula protrudes northward. San Francisco is at its tip. Bay Area by Sentinel-2, 2019-03-11 (small version).jpg
Satellite photo of the San Francisco Bay Area. The San Francisco peninsula protrudes northward. San Francisco is at its tip.
Enlarged detail of the tip of the San Francisco Peninsula San Francisco Peninsula by Sentinel-2, 2019-03-11.jpg
Enlarged detail of the tip of the San Francisco Peninsula

The San Francisco Peninsula is a peninsula in the San Francisco Bay Area that separates San Francisco Bay from the Pacific Ocean. On its northern tip is the City and County of San Francisco. Its southern base is in northern Santa Clara County, including the cities of Sunnyvale, Palo Alto, Mountain View, 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, Burlingame, Colma, Daly City, East Palo Alto, El Granada, Foster City, Hillsborough, Half Moon Bay, La Honda, Loma Mar, Los Altos, Menlo Park, Millbrae, Mountain View, Pacifica, Palo Alto, Pescadero, Portola Valley, Redwood City, San Bruno, San Carlos, San Mateo, South San Francisco, Sunnyvale, and Woodside.


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. [1]


In 1795, Governor Diego de Borica gave José Darío Argüello a Spanish land grant known as Rancho de las Pulgas. [2] This rancho was the largest grant on the peninsula consisting of 35,260 acres (142.7 km2). [2]

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, along San Francisco Bay; the west and south-central portions of the Peninsula are mostly rural, unincorporated and unorganised areas.

A substantial portion of Silicon Valley 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. [3] [4] [5]

Geography and transportation

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. 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 Santa Cruz Mountains, and SR 1 on the west along the Pacific, and SR 85 which forms the southern end of the Peninsula. The Caltrain commuter rail line runs roughly parallel to the El Camino Real (State Route 82) and Highway 101 corridors.

Major highways

The bridges in the Peninsula include the Dumbarton Bridge, the San Francisco - Oakland Bay Bridge, the San Mateo-Hayward Bridge and the Golden Gate Bridge.

Along the center line of the Peninsula is the northern half of the Santa Cruz Mountains, formed by the action of plate tectonics along the San Andreas Fault. In the middle of the Peninsula along the fault is the Crystal Springs Reservoir. Just north of the Crystal Springs reservoir is San Andreas Lake, after which the geologic fault was originally named. [6]

Environmental features

The San Francisco Peninsula contains a variety of habitats including estuarine, marine, oak woodland, redwood forest, coastal scrub and oak savanna. There are numerous species of wildlife present, especially along the San Francisco Bay estuarine shoreline, San Bruno Mountain, Fitzgerald Marine Reserve and the forests 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, all of which are endemic to San Mateo County. The endangered California clapper rail is also found on the shores of San Francisco Bay, in the cities of Belmont and San Mateo.

A number of noteworthy parks and nature preserves are found on the San Francisco Peninsula, including:

Notable structures

There are a number of well-known structures and complexes on the San Francisco Peninsula:

See also

Related Research Articles

Dumbarton Bridge (California) Southernmost bridge crossing the San Francisco Bay

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Palo Alto, California City in California in the United States

Palo Alto 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.

San Mateo County, California County in California, United States

San Mateo County, officially the County of San Mateo, is a county located in the U.S. state of California. As of the 2020 census, the population was 764,442. Redwood City is the county seat, and the third most populated city following Daly City and San Mateo. San Mateo County is included in the San Francisco-Oakland-Berkeley, CA MSA, Silicon Valley, and is part of the San Francisco Bay Area, the nine counties bordering San Francisco Bay. It covers most of the San Francisco Peninsula. San Francisco International Airport is located in the northeastern area of the county and is approximately 7 miles south of the city and county limits of San Francisco. The county's built-up areas are mostly suburban, and are home to several corporate campuses.

Interstate 280 (I-280) is a 57.5-mile-long (92.5 km) major north–south auxiliary Interstate Highway in the San Francisco Bay Area of Northern California. It runs from I-680 and US 101 in San Jose to King and Fifth Streets in San Francisco, running just to the west of the larger cities of San Francisco Peninsula for most of its route.

Bayshore Freeway Freeway in California

The Bayshore Freeway is a part of U.S. Route 101 in the San Francisco Bay Area of the U.S. state of California. It runs along the west shore of the San Francisco Bay, connecting San Jose with San Francisco. Within the city of San Francisco, the freeway is also known as James Lick Freeway, named after the California philanthropist. The road was originally built as a surface road, the Bayshore Highway, and later upgraded to freeway standards. Before 1964, it was mostly marked as U.S. Route 101 Bypass, with US 101 using the present State Route 82.

California State Route 82 Highway in California

State Route 82 is a state highway in the U.S. state of California that runs from Interstate 880 (I-880) in San Jose to I-280 in San Francisco following the San Francisco Peninsula. It is the spinal arterial road of the peninsula and runs parallel to the nearby Caltrain line along much of the route. For much of its length, the highway is named El Camino Real and formed part of the historic El Camino Real mission trail. It passes through and near the historic downtowns of many Peninsula cities, including Burlingame, San Mateo, Redwood City, Menlo Park, Palo Alto, Mountain View, and Sunnyvale, and through some of the most walkable and transit-oriented neighborhoods in the region.

Area code 650 Area code for San Mateo County and parts of Santa Clara County, California

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SamTrans Public transit operator in San Mateo County, California

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California State Route 35 Highway in California

State Route 35, generally known as Skyline Boulevard for most of its length, is a mostly two-lane state highway in the U.S. state of California. It runs along the ridge of the Santa Cruz Mountains from the high point of State Route 17 near Lexington Reservoir in Santa Clara County to State Route 1 just south of Daly City in San Mateo County, where it crosses SR 1 and loops around Lake Merced to become Sloat Boulevard in San Francisco. SR 35 then continues along Sloat Boulevard until it reaches its terminus when it meets SR 1 again at 19th Avenue.

Sequoia Union High School District School district in California, United States

The Sequoia Union High School District is a public union school district in the San Francisco Bay Area, primarily serving the southern San Mateo County communities of Atherton, Belmont, East Palo Alto, Ladera, San Carlos, Menlo Park, Portola Valley, Redwood City, and Woodside. The District currently serves more than 9,000 students, and also owns the radio station KCEA.

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Kings Mountain is an unincorporated community in San Mateo County, California, located along State Route 35 between Skeggs Point and Pise Mountain. This is about seven miles (11 km) north of Woodside Road (SR84). In the U.S. Geological Survey, National Geographic Names Database, the area is identified only as a geographic feature of type "summit" and not as a populated place. The community is inside area code 650 and uses the Woodside ZIP Code 94062.

San Francisquito Creek

San Francisquito Creek is a creek that flows into southwest San Francisco Bay in California, United States. Historically it was called the Arroyo de San Francisco by Juan Bautista de Anza in 1776. San Francisquito Creek courses through the towns of Portola Valley and Woodside, as well as the cities of Menlo Park, Palo Alto, and East Palo Alto. The creek and its Los Trancos Creek tributary define the boundary between San Mateo and Santa Clara counties.

Pacific Skyline Council

One of the six Boy Scouts of America councils that serves the San Francisco Bay area, the Pacific Skyline Council was founded in 1940 as the Stanford Area Council (#031). In 1994, the Stanford Area Council merged with the San Mateo County Council (#020) to form the current council which serves youth in San Mateo County and northern Santa Clara county.

Ravenswood High School was a public high school located in East Palo Alto, California, United States. Opened in 1958, it served the East Palo Alto area of San Mateo County until its closure in 1976. In 1958 its enrollment was 629 students. During the existence of Ravenswood, East Palo Alto was the low-income area in the shadow of its more affluent neighbors Menlo Park, Atherton and Palo Alto. The city of Palo Alto, while adjacent and sharing the same zip code, is a completely different city in Santa Clara County. Ravenswood was part of the Sequoia Union High School District, which also serves the southern San Mateo County cities of Belmont, Redwood City, San Carlos, and Woodside.

Peninsula Library System

The Peninsula Library System (PLS) is a consortium of public and community college libraries in San Mateo County, California, United States, which serves the part of the San Francisco Bay Area known as "The Peninsula". The system has dozens of branches in local communities and at various area community colleges, a bookmobile, and automated book kiosks called Library-a-Go-Go.

Peninsula Athletic League (PAL) is a high school athletic conference in California, part of the CIF Central Coast Section of the California Interscholastic Federation. It comprises 17 high schools generally around San Mateo County, California. There are also nine smaller schools, designated supplemental members, of which four are located in Santa Clara County. The seventeen sports offered are divided into different divisions depending on the strength of the school's program.


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  2. 1 2 "Early days in Menlo Park". 2002. Archived from the original on 2011-05-04. Retrieved 2010-05-04.
  3. Accessed November 20, 2021.
  4. Boxall, Bettina; St. John, Paige (November 10, 2018). "California's most destructive wildfire should not have come as a surprise". Los Angeles Times . Retrieved May 8, 2022.
  5. "Advancing Drought Science and Preparedness across the Nation". National Integrated Drought Information System. Archived from the original on November 11, 2018. Retrieved May 8, 2022.
  6. Carol S. Prentice, "Andrew Cowper Lawson", in Classic Cordilleran Concepts: A View from California, Special paper 338, Boulder, Colorado: Geological Society of America, 1999, ISBN   9780813723389, p. 70.
  7. Archived November 15, 2011, at the Wayback Machine

Coordinates: 37°35′00″N122°24′04″W / 37.58333°N 122.40111°W / 37.58333; -122.40111