Northern California Explained

Northern California
Subdivision Type:Country
Subdivision Name:United States
Subdivision Type1:State
Subdivision Type2:Major cities
Subdivision Name1:California
Subdivision Name2:San Jose
San Francisco
Fresno
Sacramento
Oakland
Stockton
Fremont
Modesto
Santa Rosa
Salinas
Hayward
Sunnyvale
Visalia
Chico
Redding
San Mateo
San Rafael
Eureka
Susanville
Seat Type:Largest city
Seat:San Jose
Population As Of:2020
Population Total:15,775,319

Northern California (commonly shortened to NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California, spanning the northernmost 48 of the state's 58 counties.[1] [2] Northern California in its largest definition is determined by dividing the state into two regions, the other being Southern California. The main northern population centers include the San Francisco Bay Area (anchored by the cities of San Jose, San Francisco, and Oakland), the Greater Sacramento area (anchored by the state capital Sacramento), the Redding, California, area south of the Cascade Range, and the Metropolitan Fresno area (anchored by the city of Fresno). Northern California also contains redwood forests, along with most of the Sierra Nevada, including Yosemite Valley and part of Lake Tahoe, Mount Shasta (the second-highest peak in the Cascade Range after Mount Rainier in Washington), and most of the Central Valley, one of the world's most productive agricultural regions. Northern California is also home to Silicon Valley, the global headquarters for some of the most powerful tech and Internet-related companies in the world, including Meta, Apple, Google, and Nvidia.

The Northern California Megaregion, one of the 11 megaregions of the United States is centered in Northern California, and extends from Metropolitan Fresno north to Greater Sacramento, and from the Bay Area east across Nevada state line to encompass the entire Lake TahoeReno area.[3]

Evidence of Native American habitation in the area dates from at least 19,000 years ago[4] and successive waves of arrivals led to one of the most densely populated areas of pre-Columbian North America. The arrival of European explorers from the early 16th to the mid-18th centuries did not establish European settlements in northern California. In 1770, the Spanish mission at Monterey was the first European settlement in the area, followed by other missions along the coast—eventually extending as far north as Sonoma County.[5]

Description

Northern California is not a formal geographic designation. Historically, the state was divided by the Tehachapi Mountains which was a barrier to travelers before highways were built, and remains a bioregion barrier. This geographical barrier curves from Point Conception at the Pacific Ocean eastward through Mount Pinos, Tejon Pass and Tehachapi Pass, then cuts northward through the Sierra Nevada mountain range to Mount Patterson and the Nevada border. The Mojave Desert and the Great Basin Desert are separated from Northern California by mountain ranges in this definition of bioregions.[6] [7]

California's north–south midway division is around 37°N, near the level of Morgan Hill and Chowchilla. (The geographic center of California is at 37.1661°N -119.4494°W near North Fork, northeast of Fresno.[8]) Popularly, though, "Northern California" usually refers to the state's northernmost 48 counties. Because of California's large size and diverse geography, the state can be subdivided in other ways as well. For example, the Central Valley is a region that is distinct both culturally and topographically from coastal California, though in northern versus southern California divisions, the Sacramento Valley and most of the San Joaquin Valley are usually placed in northern California. Some observers describe three partitions of California, with north and south sections separated by Central California.

The state is often considered as having an additional division north of the urban areas of the San Francisco Bay Area and Sacramento metropolitan areas. Extreme northern residents have felt under-represented in state government and, in 1941, attempted to form a new state with southwestern Oregon to be called Jefferson, or more recently to introduce legislation to split California into two or three states.

The coastal area north of the Bay Area is often referred to as the North Coast, touching the counties of Mendocino, Lake, Humboldt, and Del Norte. The interior region north of Sacramento metropolitan area is referred to by locals as the Northstate, consisting of about 20 counties.[9]

"Northern California" was used by Tim Draper as the name of the northernmost state to be created by splitting California into three new states. The bill, Cal 3, was prevented from appearing on the 2018 California ballot because of a constitutional review by the Supreme Court of California.[10]

Significance

Since the events of the California Gold Rush, Northern California has been a leader on the world's economic, scientific, and cultural stages. From the development of gold mining techniques and logging practices in the 19th century that were later adopted around the world, to the development of world-famous and online business models (such as Apple, Hewlett-Packard, Google, Yahoo!, and eBay), northern California has been at the forefront of new ways of doing business. In science, advances range from being the first to isolate and name fourteen transuranic chemical elements, to breakthroughs in microchip technology. Cultural contributions include the works of Ansel Adams, George Lucas, and Clint Eastwood, as well as beatniks, the Summer of Love, winemaking, the cradle of the international environmental movement, and the open, casual workplace first popularized in the Silicon Valley dot-com boom and now widely in use around the world. Other examples of innovation across diverse fields range from Genentech (development and commercialization of genetic engineering) to CrossFit as a pioneer in extreme human fitness and training.It is also home to one of the largest Air Force Bases on the West Coast, and the largest in California by square meters, Travis Air Force Base.

Cities

Northern California's largest metropolitan area is the San Francisco Bay Area which consists of 9 counties: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and Sonoma counties. The Bay Area consists of the major cities of San Jose, San Francisco, Oakland, and their many suburbs. Although not a part of the Bay Area, in recent years the Bay Area has drawn more commuters from as far as Central Valley cities such as Sacramento, Stockton, Fresno, Turlock and Modesto. These cities in the central part of the Central Valley and Sierra Nevada foothills may be viewed as part of a single megalopolis. The 2010 U.S. Census showed that the Bay Area grew at a faster rate than the Greater Los Angeles Area while Greater Sacramento had the largest growth rate of any metropolitan area in California.

The state's larger inland cities are considered part of Northern California in cases when the state is divided into two parts. Key cities in the region which are not in major metropolitan areas include Eureka on the far North Coast, Redding, at the northern end of the Central Valley, Chico, and Yuba City in the mid-north of the Central Valley, as well as Fresno and Visalia on the southern end. Though smaller in each case, with the notable exception of Fresno, than the larger cities of the general region, these smaller regional centers are often of historical and economic importance for their respective size, due to their locations, which are primarily rural or otherwise isolated.

History

Prehistory to 1847

Inhabited for millennia by Native Americans, from the Shasta tribe in the north, to the Miwoks in the central coast and Sierra Nevada, to the Yokuts of the southern Central Valley, northern California was among the most densely populated areas of pre-Columbian North America.[11]

European explorers

The first European to explore the coast was Juan Rodríguez Cabrillo, sailing for the Spanish Crown; in 1542, Cabrillo's expedition sailed perhaps as far north as the Rogue River in today's Oregon.[12] Beginning in 1565, the Spanish Manila galleons crossed the Pacific Ocean from Mexico to the Spanish Philippines, with silver and gemstones from Mexico. The Manila galleons returned across the northern Pacific, and reached North America usually off the coast of northern California, and then continued south with their Asian trade goods to Mexico.

In 1579, northern California was visited by the English explorer Sir Francis Drake who landed north of today's San Francisco and claimed the area for England. In 1602, the Spaniard Sebastián Vizcaíno explored California's coast as far north as Monterey Bay, where he went ashore. Other Spanish explorers sailed along the coast of northern California for the next 150 years, but no settlements were established.[13]

Spanish era

The first European inhabitants were Spanish missionaries, who built missions along the California coast. The mission at Monterey was first established in 1770, and at San Francisco in 1776. In all, ten missions stretched along the coast from Sonoma to Monterey (and still more missions to the southern tip of Baja California). In 1786, the French signaled their interest in the northern California area by sending a voyage of exploration to Monterey.

The first twenty years of the 19th century continued the colonization of the northern California coast by Spain. By 1820, Spanish influence extended inland approximately 25 to 50miles from the missions. Outside of this zone, perhaps 200,000 to 250,000 Native Americans continued to lead traditional lives. The Adams-Onís Treaty, signed in 1819 between Spain and the young United States, set the northern boundary of the Spanish claims at the 42nd parallel, effectively creating today's northern boundary of northern California.

Russian presence

In 1812, the Russian state-sponsored Russian-American Company established Fort Ross, a fur trading outpost on the coast of today's Sonoma County. Fort Ross was the southernmost Russian settlement, located some 60miles north of Spanish colonies in San Francisco. In 1839, the settlement was abandoned due to its inability to meet resource demands, and the increasing Mexican and American presence in the region.[14]

Mexican era

After Mexico gained independence from Spain in 1821, Mexico continued Spain's missions and settlements in northern California as well as Spain's territorial claims. The Mexican Californios (Spanish-speaking Californians) in these settlements primarily traded cattle hides and tallow with American and European merchant vessels.

In 1825, the Hudson's Bay Company established a major trading post just north of today's Portland, Oregon. British fur trappers and hunters then used the Siskiyou Trail to travel throughout northern California.[15] The leader of a further French scientific expedition to northern California, Eugene Duflot de Mofras, wrote in 1840 "...it is evident that California will belong to whatever nation chooses to send there a man-of-war and two hundred men."[16] By the 1830s, a significant number of non-Californios had immigrated to northern California. Chief among these was John Sutter, a European immigrant from Switzerland, who was granted 48827acres centered on the area of today's Sacramento.[17]

American interest

American trappers began entering northern California in the 1830s. In 1834, American visionary Ewing Young led a herd of horses and mules over the Siskiyou Trail from missions in northern California to British and American settlements in Oregon. Although a small number of American traders and trappers had lived in northern California since the early 1830s, the first organized overland party of American immigrants to arrive in northern California was the Bartleson-Bidwell Party of 1841 via the new California Trail. Also in 1841, an overland exploratory party of the United States Exploring Expedition came down the Siskiyou Trail from the Pacific Northwest. In 1846, the Donner Party earned notoriety as they struggled to enter northern California.

Californian independence and beginning of the United States era

When the Mexican–American War was declared on May 13, 1846, it took almost two months (mid-July 1846) for word to get to California. On June 14, 1846, some 30 non-Mexican settlers, mostly Americans, staged a revolt and seized the small Mexican garrison in Sonoma. They raised the "Bear Flag" of the California Republic over Sonoma. The "Bear Flag Republic" lasted only 26 days, until the U.S. Army, led by John Frémont, took over on July 9.[18] The California state flag today is based on this original Bear Flag, and continues to contain the words "California Republic."

Commodore John Drake Sloat ordered his naval forces to occupy Yerba Buena (present San Francisco) on July 7 and within days American forces controlled San Francisco, Sonoma, and Sutter's Fort in Sacramento. The treaty ending the Mexican–American War was signed on February 2, 1848, and Mexico formally ceded Alta California (including all of present-day northern California) to the United States.

Gold Rush and California statehood

The California Gold Rush took place almost exclusively in northern California from 1848 to 1855. It began on January 24, 1848, when gold was discovered at Sutter's Mill in Coloma.[19] News of the discovery soon spread, resulting in some 300,000 people coming to California from the rest of the United States and abroad. San Francisco grew from a tiny hamlet, home to about 1,000 Californios into a boomtown of over 50,000 people in the 12 years between 1848 and 1860.[20] [21] New roads, churches, and schools were built, and new towns sprung up, aided in part by the development of new methods of transportation such as steamships which came into regular service and railroads which now connected the coasts. The Gold Rush also had negative effects: American colonists chose to use genocide as a tool to remove the Indigenous people so that they could look for gold on their land.

The Gold Rush also increased pressure to make California a U.S. state. Pro-slavery politicians initially attempted to permanently divide northern and southern California at 36 degrees, 30 minutes, the line of the Missouri Compromise. But instead, the passing of the Compromise of 1850 enabled California to be admitted to the Union as a free state.[22]

Population and agricultural expansion (1855–1899)

The decades following the Gold Rush brought dramatic expansion to northern California, both in population and economically – particularly in agriculture. The completion of the First transcontinental railroad in 1869, with its terminus in Sacramento (and then later, Oakland), meant that northern California's agricultural produce (and some manufactured goods) could now be shipped economically to the rest of the United States. In return, immigrants from the rest of the United States (and Europe) could comfortably come to northern California. A network of railroads spread throughout northern California, and in 1887, a rail link was completed to the Pacific Northwest. Almost all of these railways came under the control of the Southern Pacific Railroad, headquartered in San Francisco, and San Francisco continued as a financial and cultural center.

Substantial tensions during this era included nativist sentiments (primarily against Chinese immigrants),[23] tensions between the increasing power of the Southern Pacific Railroad and small farmers, and the beginnings of the labor union movement.

Economy

Northern California's economy is noted for being the de facto world leader in high-tech industry (software, semiconductor/micro-electronics, biotechnology and medical devices/instruments), as well as being known for clean power, biomedical, government, and finance. Other significant industries include tourism, shipping, manufacturing, and agriculture. Its economy is diverse, though more concentrated in high technology. It is home to the state capital, as well as several Western United States regional offices in San Francisco, such as the Federal Reserve and 9th Circuit Court.

Climate

Northern California has a warm or mild to cool climate, in which the Sierra mountains gets snow in the late fall through winter and occasionally into spring. Summers are mild along the coast and generally warm and dry, while winters are cool and usually wet. The high temperatures range from 50s °F (10–15 °C) to 30s °F (−1 – +4 °C) in the winters while summers temperature range is 90s °F (32–37 °C) to 60s °F (15–20 °C) or 50s °F (10–15 °C), with highs well into the 100s °F (37–42 °C) for the Sacramento region. Snow covers the mountains (generally above 3000feet) in mid January through February. Fog occurs infrequently or occurs normally in the west and coast, especially in the summer, creating some of the coolest summer conditions in North America.[24] Since the first decade of the 21st century, droughts and wildfires have increased in frequency as a consequence of climate change.[25] [26]

Population

The population of the forty-eight counties of northern California has shown a steady increase over the years.[27] [28]

The largest percentage increase outside the Gold Rush era (52%) came during the 1940s, as the region was the destination of many post-War veterans and their families, attracted by the greatly expanding industrial base and (often) by their time stationed in northern California during World War II. The largest absolute increase occurred during the 1980s (over 2.1 million person increase), attracted by job opportunities in part by the expansion taking place in Silicon Valley and the Cold War–era expansion of the defense industry. Since the 2000 U.S. Census, Northern California has grown at a faster rate than Southern California due to the strong economic performances of the Bay Area and Sacramento.[29]

Parks and other protected areas

National Park System

See main article: List of areas in the United States National Park System and List of national parks of the United States. The U.S. National Park System controls a large and diverse group of parks in northern California. The best known is Yosemite National Park, which is displayed on the reverse side of the California state quarter. Other prominent parks are the Kings Canyon-Sequoia National Park complex, Redwood National Park, Pinnacles National Park, Lassen Volcanic National Park and the largest in the contiguous forty-eight states, Death Valley National Park.

National Monuments and other federally protected areas

See main article: List of national monuments of the United States, United States National Marine Sanctuary, List of National Wildlife Refuges of the United States and List of national forests of the United States. Other areas under federal protection include Muir Woods National Monument, Giant Sequoia National Monument, Devils Postpile National Monument, Lava Beds National Monument, Point Reyes National Seashore, the Monterey Bay National Marine Sanctuary, and the Cordell Bank and Gulf of the Farallones National Marine Sanctuaries (both off the coast of San Francisco). Included within the latter National Marine Sanctuary is the Farallon National Wildlife Refuge; this National Wildlife Refuge is one of approximately twenty-five such refuges in northern California. National forests occupy large sections of northern California, including the Shasta–Trinity, Klamath, Modoc, Lassen, Mendocino, Eldorado, Tahoe, and Sequoia national forests, among others. Included within (or adjacent to) national forests are federally protected wilderness areas, including the Trinity Alps, Castle Crags, Granite Chief, and Desolation wilderness areas.

In addition, the California Coastal National Monument protects all islets, reefs, and rock outcroppings from the shore of northern California out to a distance of 12nmi, along the entire northern California coastline. In addition, the National Park Service administers protected areas on Alcatraz Island, the Golden Gate National Recreation Area, Whiskeytown–Shasta–Trinity National Recreation Area, and the Smith River National Recreation Area. The NPS also administers the Manzanar National Historic Site in Inyo County, the Rosie the Riveter World War II Home Front National Historical Park in Richmond, and the Tule Lake National Monument outside of Tulelake.

Other

Educational institutions

Northern California hosts a number of world-renowned universities including Stanford University and University of California, Berkeley. Top-tier public graduate schools include Boalt Hall and Hastings law schools and UC San Francisco (a top-ranked medical school) and UC Davis School of Veterinary Medicine, the largest veterinary school in the United States.

Public

Private

(Partial list)

Research

(Partial list)

Counties

Regions

The following regions are entirely or partly within northern California:

Cities and towns with more than 50,000 inhabitants

CityPopulation (2020)[30]
Alameda78,280
Antioch115,291
Berkeley124,321
Brentwood64,292
Chico101,475
Citrus Heights87,583
Clovis120,124
Concord125,410
Cupertino60,381
Daly City104,901
Davis66,850
Dublin72,589
Elk Grove176,124
Fairfield119,881
Folsom80,454
Fresno542,107
Fremont230,504
Gilroy59,520
Hanford57,990
Hayward162,954
Livermore87,955
Lodi66,348
Madera66,224
Manteca83,498
Merced86,333
Milpitas80,273
Modesto218,464
Mountain View82,376
Napa79,246
Novato53,225
Oakland440,646
Palo Alto68,572
Petaluma59,776
Pittsburg76,416
Pleasanton79,871
Porterville62,623
Rancho Cordova79,332
Redding93,611
Redwood City84,292
Richmond116,448
Rocklin71,601
Roseville147,773
Sacramento524,943
Salinas163,542
San Francisco873,965
San Jose1,013,240
San Leandro91,008
San Mateo105,661
San Rafael61,271
San Ramon84,605
Santa Clara127,647
Santa Cruz62,956
Santa Rosa178,127
South San Francisco66,105
Stockton320,804
Sunnyvale155,805
Tracy93,000
Tulare68,875
Turlock72,740
Union City70,143
Vacaville102,386
Vallejo126,090
Visalia141,384
Walnut Creek70,127
Watsonville52,590
West Sacramento53,915
Woodland61,032
Yuba City70,117

Metropolitan areas

Northern California is home to three of the state's four extended metropolitan areas, which are home to over three-fourths of the region's population as of the 2010 United States Census:[31]

Metropolitan regionPopulation
San Francisco Bay Area7,468,390
Greater Sacramento2,461,780
Metropolitan Fresno1,081,315

Major business districts

The following are major central business districts:

Transportation

See also articles:

See also categories:

Airports

See main article: List of airports in California.

There are 11 airports in Northern California categorized as Primary Service Commercial airports by the FAA:[32]

Airport ID City Category 2018 Enplanements
San Francisco International AirportSFO Large Hub 27,794,154
San Jose International AirportSJC Medium Hub 7,037,144
Oakland International AirportOAK Medium Hub 6,687,963
Sacramento International AirportSMFSacramentoMedium Hub 5,907,901
Fresno Yosemite International AirportFATSmall Hub 853,538
Charles M. Schulz–Sonoma County AirportSTSNon Hub 217,994
Monterey Regional AirportMRYNon Hub 188,046
Stockton Metropolitan AirportSCKNon Hub 99,258
Arcata-Eureka AirportACVNon Hub 69,604
Redding Municipal AirportRDDNon Hub 42,775
Mammoth Yosemite AirportMMHNon Hub 23,522

Railroad

Major transit organizations

Major transit ferries

Freeways

Interstate highways

U.S. Routes

Principal state highways

Communication

Telephone area codes

Sports

See also: Bay Bridge Series.

Major league professional sports teams

SportLeagueTeamVenue City
BaseballMLBOakland Athletics (American League)RingCentral ColiseumOakland
San Francisco Giants (National League)Oracle ParkSan Francisco
BasketballNBAGolden State WarriorsChase CenterSan Francisco
Sacramento KingsGolden 1 CenterSacramento
FootballNFLSan Francisco 49ersLevi's StadiumSanta Clara
Ice hockeyNHLSan Jose SharksSAP CenterSan Jose
SoccerMLSSan Jose EarthquakesAvaya StadiumSan Jose
Indoor footballIFLBay Area PanthersSAP CenterSan Jose

College sports teams

Sports venues

Sporting events

See also

External links

Notes and References

  1. News: September 7, 2014. Westward Tilt: Northern California . Neil . Morgan . Lodi News-Sentinel . Lodi, California . April 19, 1963.
  2. Book: Kent Guide Manual (Harrison Narcotic Law) and Progressional Registry . 6 . John E. Kent . The Service Press . 1917 . San Francisco.
  3. Web site: Gabriel. Metcalf. Egon . Terplan. The northern California megaregion. November–December 2007. The Urbanist. San Francisco Planning and Urban Research Association. November 21, 2009 .
  4. Web site: Sep 2019. Megan I. Gannon / 4. September 4, 2019. The Knotty Question of When Humans Made the Americas Home. July 29, 2021. SAPIENS. en-US.
  5. Web site: Home County of Sonoma. July 29, 2021. sonomacounty.ca.gov.
  6. News: Smith . Thomas . 2023-04-23 . Where Does Southern California Stop and Northern California Start? . 2023-04-25 . Bay Area Telegraph . en-US . April 25, 2023 . https://web.archive.org/web/20230425141209/https://bayareatelegraph.com/2023/04/23/where-does-southern-california-stop-and-northern-california-start/ . live .
  7. Book: The Biosphere and the Bioregion: Essential Writings of Peter Berg . 265 . Cheryll Glotfelty . Eve Quesnel . Peter Berg . 2014 . Routledge . 9781134504091 . October 9, 2023 . October 23, 2023 . https://web.archive.org/web/20231023205057/https://books.google.com/books?id=dF4KBAAAQBAJ&pg=PA265 . live .
  8. Web site: Finding California's Geographic Center . O'Keefe . Rob . August 9, 2017 . Rediscovering the Golden State . May 12, 2023.
  9. Web site: A separatist state of mind . Wiles . Tay . January 22, 2018 . High Country News . en-us . https://web.archive.org/web/20180617023048/https://www.hcn.org/issues/50.1/communities-rural-discontent-finds-a-home-in-the-state-of-jefferson . June 17, 2018 . live . August 23, 2018 .
  10. Web site: Radical plan to split California into three states earns spot on November ballot. Myers. John. Los Angeles Times. June 13, 2018. June 14, 2018.
  11. Web site: California Indian Tribes map . CaliforniaPrehistory.com . R.F. Heizer . 1966 . February 10, 2007 . April 30, 2011 . https://web.archive.org/web/20110430112732/http://www.californiaprehistory.com/tribmap.html . dead .
  12. Web site: Juan Rodríguez Cabrillo: A Voyage of Discovery . U.S. National Park Service . February 10, 2007.
  13. Web site: Introduction--Early History of the California Coast--A National Register of Historic Places Travel Itinerary. July 29, 2021. www.nps.gov.
  14. Web site: Russian Expansion to America (Russian American Company in California).
  15. Web site: Hunters and Trappers at Upper Soda Springs . Museum of the Siskiyou Trail . February 10, 2007.
  16. Book: Bancroft, Hubert Howe . History of California, 1840–1845, Volume 4 . 1886 . A. L. Bancroft. Hubert Howe Bancroft . 9475460.
  17. Web site: Sutter's Fort Historic State Park . California Department of Parks & Recreation . February 10, 2007.
  18. Web site: American Transition to Early Statehood . California Department of Parks & Recreation . February 10, 2007.
  19. "[E]vents from January 1848 through December 1855 [are] generally acknowledged as the 'Gold Rush' .... After 1855, California gold mining changed and is outside the 'rush' era." Web site: The Gold Rush of California: A Bibliography of Periodical Articles. California State University, Stanislaus. 2002. January 23, 2008. March 12, 2012. https://web.archive.org/web/20120312213110/http://library.csustan.edu/bsantos/goldrush/GoldTOC.htm. dead.
  20. Book: Richards, Rand, 1949-. Historic San Francisco : a concise history and guide. 1991. Heritage House Publishers. 1-879367-00-9. San Francisco. 23463043.
  21. Web site: 1860 Census: Population of the United States. October 10, 2020. The United States Census Bureau. EN-US.
  22. Web site: June 15, 2021. Living shorelines could help California coasts adapt to rising sea levels. July 29, 2021. Grist. en-us.
  23. Web site: California Labor History Archive. July 29, 2021. California Labor Federation. October 29, 2016 . en-US.
  24. Web site: Northern California. July 29, 2021. www.ccul.org. January 26, 2021 . en-us.
  25. News: Boxall . Bettina . St. John . Paige . November 10, 2018 . California's most destructive wildfire should not have come as a surprise . . November 11, 2018.
  26. Web site: Advancing Drought Science and Preparedness across the Nation . dead . https://web.archive.org/web/20181111042024/https://www.drought.gov/drought/ . November 11, 2018 . November 11, 2018 . National Integrated Drought Information System.
  27. Web site: Historical census data by U.S. Census Bureau. https://web.archive.org/web/20031231155609/http://countingcalifornia.cdlib.org/sas-bin/broker?_program=prd.calmatx.sas&study=histpop&file=histcnty%20histcity%20histst&varMtx=histpop_1&dtbl=histpop_1. dead. December 31, 2003. February 6, 2019.
  28. Web site: U.S. Census website. United States Census Bureau. February 6, 2019.
  29. https://www.spur.org/sites/default/files/2013-09/SPUR_The_Northern_California_Megaregion.pdf The Northern California Megaregion
  30. Web site: U.S. Census Bureau QuickFacts . United States Census Bureau . September 3, 2021.
  31. Excerpted from 2010 United States Census
  32. Web site: Passenger Boarding (Enplanement) and All-Cargo Data for U.S. Airports – Airports. Faa.gov. February 6, 2019.
  33. For current information, see nanpa.com, the North American Numbering Plan Administration site.