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 Mountain View, south of Palo Alto and north of Sunnyvale 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, Pacifica, Palo Alto, Pescadero, Portola Valley, Redwood City, San Bruno, San Carlos, San Mateo, South San Francisco, 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 unorganized 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

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]

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.


The bridges in the Peninsula include the Dumbarton Bridge, the Golden Gate Bridge, 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 Santa Cruz Mountains, and SR 1 on the west along the Pacific, and SR 85 which forms the southern end of the Peninsula.


Caltrain 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) and San Francisco's 4th and King Street stationIn addition, the peninsula has access to Bay Area Rapid Transit (BART) northward of Millbrae, connecting San Mateo County and San Francisco to the East Bay through a route over and under Daly City, Glen Park, San Francisco's Mission district, and through part of Market Street subway.

Bus service is predominantly served by SamTrans 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 East Bay and North Bay flowing through San Francisco, as neither AC Transit nor Golden Gate Transit, the primary transit operators for the East and North Bay respectively, do not serve the peninsula south of San Francisco. [7] [8]


The peninsula's sole commercial airport is San Francisco International Airport, itself connected to US 101 and BART. Access to the two other major commercial airports within the Bay Area, Oakland and San Jose, requires usage of BART, CalTrain, or the VTA.

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

<span class="mw-page-title-main">Dumbarton Bridge (California)</span> Southernmost bridge crossing the San Francisco Bay

The Dumbarton Bridge is the southernmost of the highway bridges across San Francisco Bay in California. Carrying over 70,000 vehicles and about 118 pedestrian and bicycle crossings daily, it is the shortest bridge across San Francisco Bay at 1.63 miles. Its eastern end is in Fremont, near Newark in the San Francisco Bay National Wildlife Refuge, and its western end is in Menlo Park. Bridging State Route 84 across the bay, it has three lanes each way and a separated bike/pedestrian lane along its south side. Like the San Mateo Bridge to the north, power lines parallel the bridge.

<span class="mw-page-title-main">Palo Alto, California</span> City in California, 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.

<span class="mw-page-title-main">San Mateo County, California</span> 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, even though the airport itself is assigned a San Francisco postal address. The county's built-up areas are mostly suburban, and are home to several corporate campuses.

<span class="mw-page-title-main">Menlo Park, California</span> City in California, United States

Menlo Park is a city at the eastern edge of San Mateo County within the San Francisco Bay Area of California in the United States. It is bordered by San Francisco Bay on the north and east; East Palo Alto, Palo Alto, and Stanford to the south; and Atherton, North Fair Oaks, and Redwood City to the west. It had 33,780 residents at the 2020 United States census. It is home to the corporate headquarters of Meta, and is where Google, Roblox Corporation and Round Table Pizza were founded. The train station holds the record as the oldest continually operating train station in California. It is one of the most educated cities in California and the United States; nearly 70% of residents over 25 have earned a bachelor's degree or higher.

<span class="mw-page-title-main">East Palo Alto, California</span> City in California, United States

East Palo Alto is a city in San Mateo County, California, United States. As of the 2020 census, the population of East Palo Alto was 30,034. It is situated on the San Francisco Peninsula, roughly halfway between the cities of San Francisco and San Jose. To the north and east is the San Francisco Bay, to the west is the city of Menlo Park, and to the south the city of Palo Alto. Despite being called "East" Palo Alto, the city is directly north of Palo Alto. While often incorrectly assumed to be part of the city of Palo Alto, East Palo Alto has always been a separate entity since its founding as an unincorporated community and its incorporation in July 1983. It is also in San Mateo County, while Palo Alto is in Santa Clara County. The two cities are separated only by San Francisquito Creek and, largely, the Bayshore Freeway. The revitalization projects in 2000, and high income high-tech professionals moving into new developments, including employees from Google and Facebook, have begun to eliminate the cultural and economic differences between the two cities. East Palo Alto and Palo Alto share both telephone area codes and postal ZIP codes.

<span class="mw-page-title-main">Northern California</span> American geographic and cultural region

Northern California is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers include the San Francisco Bay Area, the Greater Sacramento area, the Redding, California, area south of the Cascade Range, and the Metropolitan Fresno area. Northern California also contains redwood forests, along with most of the Sierra Nevada, including Yosemite Valley and part of Lake Tahoe, Mount Shasta, and most of the Central Valley, one of the world's most productive agricultural regions.

<span class="mw-page-title-main">Interstate 280 (California)</span> Interstate highway in California

Interstate 280 (I-280) is a 57.22-mile-long (92.09 km) major north–south auxiliary Interstate Highway in the San Francisco Bay Area of Northern California. It runs from I-680 and US Route 101 (US 101) in San Jose to King and 5th streets in San Francisco, running just to the west of the larger cities of San Francisco Peninsula for most of its route.

<span class="mw-page-title-main">Santa Clara Valley Transportation Authority</span> Public transit operator in Santa Clara County, California

The Santa Clara Valley Transportation Authority, more commonly known simply as the Valley Transportation Authority (VTA), is a special district responsible for public transit services, congestion management, specific highway improvement projects, and countywide transportation planning for Santa Clara County, California. It serves San Jose, California, and the surrounding Silicon Valley. It is one of the governing parties for the Caltrain commuter rail line that serves the county. In 2022, the VTA's public transportation services had a combined ridership of 21,381,600, or about 76,000 per weekday as of the fourth quarter of 2022.

<span class="mw-page-title-main">California State Route 82</span> 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.

<span class="mw-page-title-main">Area code 650</span> Area code for San Mateo County and parts of Santa Clara County, California

Area code 650 is a telephone area code in the North American Numbering Plan (NANP) for the San Francisco Bay Area in the U.S. state of California. It was split from area code 415 on August 2, 1997, and includes most of San Mateo County, part of San Francisco, and the northwestern portion of Santa Clara County including Palo Alto, Mountain View, and Los Altos.

<span class="mw-page-title-main">SamTrans</span> Public transit operator in San Mateo County, California

SamTrans 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 portions of San Francisco and Palo Alto. SamTrans also operates commuter shuttles to BART stations and community shuttles. Service is largely concentrated on the east side of the Santa Cruz Mountains, and, in the central county, I-280, leaving coast-side service south of Pacifica spotty and intermittent.

<span class="mw-page-title-main">California State Route 35</span> 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.

<span class="mw-page-title-main">Transportation in the San Francisco Bay Area</span> Overview of transportation in the San Francisco Bay Area, California, United States

People in the San Francisco Bay Area rely on a complex multimodal transportation infrastructure consisting of roads, bridges, highways, rail, tunnels, airports, seaports, and bike and pedestrian paths. The development, maintenance, and operation of these different modes of transportation are overseen by various agencies, including the California Department of Transportation (Caltrans), the Association of Bay Area Governments, San Francisco Municipal Transportation Agency, and the Metropolitan Transportation Commission. These and other organizations collectively manage several interstate highways and state routes, eight passenger rail networks, eight trans-bay bridges, transbay ferry service, local and transbay bus service, three international airports, and an extensive network of roads, tunnels, and bike paths.

<span class="mw-page-title-main">All Nighter (bus service)</span> San Francisco Bay Area late night bus service

The All Nighter is a night bus service network in the San Francisco Bay Area, California. Portions of the service shadow the rapid transit and commuter rail services of BART and Caltrain, which are the major rail services between San Francisco, the East Bay, the Peninsula, and San Jose. Neither BART nor Caltrain operate owl service due to overnight track maintenance; the All Nighter network helps fill in this service gap. The slogan is, "Now transit stays up as late as you do!"

<span class="mw-page-title-main">Pacific Skyline Council</span>

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.

<span class="mw-page-title-main">Peninsula Library System</span>

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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  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.
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  7. "Find Your Route & Stop - Riding the Bus | Golden Gate". Retrieved 2022-12-08.
  8. AC Transit. "Schedule and Fares for Daly City" (PDF). Retrieved December 8, 2022.
  9. Archived November 15, 2011, at the Wayback Machine
37°35′00″N122°24′04″W / 37.58333°N 122.40111°W / 37.58333; -122.40111