California is one of the biggest states in the US. It’s also one of the most populous, home to some of the biggest cities in the country like star-studded Los Angeles, sunny San Diego, and high-tech San Jose.
Known as “The Golden State” for the 1849 Gold Rush that brought miners from across the country, California is home to incredible landscapes, people, and cultures. It has been inhabited for thousands of years by diverse groups of people, and it is still full of life.
There are 58 counties in California, 27 of which were the original counties formed when California became a state in 1850. In this post, we’ll look at a California Counties Map and will learn about what makes some of these counties unique.
California (CA) on the US Map
Interactive Map of California Counties
Below is a map of the 58 counties of California (you can click on the map to enlarge it and to see the major city in each state).
Interactive Map of California Counties
Click on any of the counties on the map to see the county’s population, economic data, time zone, and zip code (the data will appear below the map). Data is sourced from the US Census 2021.
List of the Counties of California:
|County||Population||Per sq. km||Largest City|
|Alpine County||1,344||0.7||Mesa Vista|
|Calaveras County||45,349||17.17||Rancho Calaveras|
|Contra Costa County||1,161,643||625.6||Concord|
|Del Norte County||27,655||10.61||Crescent City|
|El Dorado County||190,568||43.08||El Dorado Hills|
|Imperial County||180,051||16.65||El Centro|
|Los Angeles County||10,019,635||953.02||Los Angeles|
|Marin County||262,387||194.67||San Rafael|
|Mariposa County||17,225||4.59||Lake Don Pedro|
|Mono County||13,291||1.68||Mammoth Lakes|
|Orange County||3,182,923||1550.02||Mission Viejo|
|Plumas County||19,631||2.97||East Quincy|
|San Benito County||63,329||17.61||Hollister|
|San Bernardino County||2,171,071||41.77||Victorville|
|San Diego County||3,296,317||302.29||San Diego|
|San Francisco County||865,933||7126.6||San Francisco|
|San Joaquin County||771,406||213.91||Stockton|
|San Luis Obispo County||282,771||33.08||El Paso de Robles|
|San Mateo County||762,488||656.23||San Mateo|
|Santa Barbara County||447,651||63.22||Santa Barbara|
|Santa Clara County||1,932,022||577.78||San Jose|
|Santa Cruz County||272,138||236.06||Santa Cruz|
|Sonoma County||492,498||120.68||Santa Rosa|
|Sutter County||99,080||63.47||Yuba City|
|Tehama County||65,345||8.55||Red Bluff|
Largest Counties in California by Population
Los Angeles County
Los Angeles County is the most populous county in both California and the United States, with a population that surpasses 10 million. It’s home to the city of Los Angeles, the county seat, which holds the distinction of being the second-largest city in the nation.
The city of Los Angeles is globally recognized for its entertainment industry, especially Hollywood, which has earned it the moniker of the “Entertainment Capital of the World.” The county is also renowned for its rich mix of cultures, offering many different ethnic cuisines, art, and music scenes.
Geographically, Los Angeles County enjoys diverse landscapes, from coastlines to mountainous regions. It is home to important educational institutions like the University of Southern California and cultural landmarks like the Getty Center, Griffith Observatory, and the Los Angeles County Museum of Art.
San Diego County
The second-most populous county in California is San Diego County, which lies at the southernmost edge of the state. There are over 3 million people that live here, and there are 18 Native American tribal reservations, the most of any county in the United States.
The county seat is the city of San Diego, the second-most populous city in the state and famous for its pleasant year-round climate, extensive beaches, and natural deep-water harbor in which the Port of San Diego was established in 1962.
San Diego County also stands out for its biotechnology and healthcare sectors. The county offers numerous outdoor recreational opportunities with places like Balboa Park and a myriad of stunning beaches. The county is also home to the San Diego Zoo, one of the largest zoos in the United States.
Cultural attractions include the USS Midway Museum and Old Town San Diego, which celebrate the region’s rich history.
Like San Diego County, California’s Orange County lies in the southern part of the state and also boasts a population of over 3 million. This county is perhaps best known for its affluent communities such as Newport Beach and Huntington Beach, as well as the city of Anaheim, where Disneyland Resort is located.
Orange County’s economy is driven by industries such as technology, healthcare, and professional services. The county is also home to important educational institutions, including the University of California, Irvine, and Chapman University.
The geography of the region is characterized by a beautiful Pacific coastline, complemented by a series of parks, trails, and recreational areas that are ideal for outdoor activities. Surfing is a popular activity in the waters off of the county’s sandy beaches.
Riverside County is California’s fourth-most populous county, situated inland from the coastal counties of the state. A key component of the “Inland Empire” region, the county is known for its desert communities like Palm Springs, a famous resort city offering a blend of natural beauty and architectural marvels.
The county spreads across the southern part of California in a roughly rectangular shape, stretching from the greater Los Angeles area in the west to the Arizona border in the east. The central and eastern portions of the county are mostly desert, and the western portion has a Mediterranean climate.
The city of Riverside is the county seat, and was founded in 1870 along the Santa Ana River. The county was named after the city when it was later formed in 1893. Before the arrival of Europeans, the land had been inhabited by several Native American groups including the Serranos, the Luisenos, the Cupenos, the Chemehuevi, and the Cahuillas.
San Bernardino County
San Bernardino County is the fifth-most populous county in California and the largest county in the contiguous United States by area, covering roughly the same amount of land as the state of West Virginia. Some boroughs and census areas of Alaska are larger.
The geography of this expansive county includes diverse landscapes, ranging from parts of the Mojave Desert to the San Bernardino Mountains. There are a multitude of outdoor activities available throughout the county, including camping, fishing, and hiking. Major cities in the county include San Bernardino, which is the county seat, and Ontario.
Several groups of Indigenous peoples have resided in the San Bernardino Valley, San Bernardino Mountains, the Mojave Desert, and along the Colorado River long before the arrival of Europeans in the 18th century. These include the Serrano, Cahuilla, Chemehuevi, Kawaiisu, Mohave, and Maricopa peoples, among others.
Smallest Counties in California by Population
With a population of only 1,344, Alpine County is the least populous county in California. It also has the lowest population density at just 0.7 people per square kilometer (0.27/mi2). Though it has a small population, the county’s location in the Sierra Nevada mountains gives it a big reputation for outdoor recreation.
Alpine’s county seat and largest community is Markleeville, a census-designated place that hosts the Alpine County Courthouse at Marklee’s Cabine Site, a historical landmark. In addition to the many high-quality hiking trails around Markleeville, it’s known for hosting the annual bicycle ride called Tour of the California Alps – Death Ride.
Alpine County was formed in 1864 from parts of Amador, Calaveras, El Dorado, Mono, and Tuolumne Counties in response to a rise in population caused by the Nevada Silver Rush. It was named for its location in the Sierra Nevada mountains, resembling the Swiss Alps.
Sierra County is tucked within the Sierra Nevada mountain range and is one of California’s least populous counties. The small population and surrounding natural beauty help to foster a close-knit community atmosphere in the county seat of Downieville and throughout the county.
The area of modern-day Sierra County has been inhabited for more than 5,000 years. Some of the Native Americans to live here before the arrival of American immigrants in 1844 were the Miwok tribe and the Washoe tribe. The county was formed from parts of Yuba County in 1852.
The forests, lakes, and mountains that populate Sierra County are perfect for outdoor pursuits, and history buffs will enjoy a visit to Downieville, which serves as a living museum of the Gold Rush Era. It also hosts the Downieville Classic mountain bike festival.
Located in the northeastern corner of California, Modoc County is a sparsely populated area known for its high desert landscapes and pine forests. The county seat is Alturas, which acts as a central hub for local ranching communities by providing necessary amenities. Alturas carries the motto, “Where the West Still Lives.”
Outside of Alturas, the rural expanse of Modoc County offers remarkable natural scenery. Most notably the Modoc National Forest and a part of the Warner Mountains, providing ample opportunities for outdoor exploration.
Modoc County also has a rich Indigenous history. The county was incorporated in 1874 and was named after a Native American tribe that lived in the area.
Despite its small population, Mono County is a popular destination for those who enjoy nature and outdoor activities. The county was founded in 1861 and is named after Mono Lake, one of the oldest lakes in the Western Hemisphere. The county seat is the unincorporated community and census-designated place, Bridgeport.
Mammoth Lakes, the county’s largest community, is renowned for its world-class skiing resort, attracting winter sports enthusiasts from around the globe. Other outdoor attractions in the county include the Mono Basin National Forest Scenic Area and the eastern entrance to Yosemite National Park.
Mono County is also home to Bodie State Historic Park, which was established in 1962 and receives thousands of tourists each year. Bodie has been a ghost town for more than a century, previously a boom town after the discovery of gold in 1859.
Trinity County occupies a portion of California’s rugged northwestern area in the lower ranges of the Cascade Mountain Range. It’s primarily forested, featuring significant portions of the Shasta-Trinity National Forest, in which outdoor activities such as hiking, backpacking, mountain climbing, and horseback riding are possible.
The county is named after the Trinity River, which flows through it, and was incorporated in 1850. The county seat and largest community is the census-designated place of Weaverville, a historic California Gold Rush town located at the foot of the Trinity Alps Wilderness Area.
Along with Alpine and Mariposa counties, Trinity County is one of three counties in California with no incorporated cities.
Notable California Counties
San Francisco County
San Francisco County is the only consolidated city-county in California, meaning it’s governed as both a city and county. It’s also the smallest county in the state by area and has the highest population density.
Known for its iconic landmarks and vibrant cultural scene, San Francisco County has a distinct identity. The Golden Gate Bridge and Park, Alcatraz Island, and Fisherman’s Wharf are just a few highlights that attract millions of tourists annually. It was also the birthplace of the 1960s counterculture movement and has a prominent LGBTQI+ community.
Economically, San Francisco County serves as a major global hub for high-tech and digital industries. It’s home to countless tech companies, including Salesforce and Uber. This economic prosperity continues to draw a young, educated workforce to the city.
The city of Sacramento, which is the county seat of the eponymous county, is also the capital of the state of California, making Sacramento County the political hub of the state. It is one of the original 27 counties formed in 1850 and is known as the “City of Trees” for its many green spaces.
The city of Sacramento is full of history, it’s home to the historic Sutter’s Fort, the homeland of the Nisenan people, and the first European colonial settlement in California’s Central Valley. The city is also home to Old Sacramento, a 296-acre district with museums and buildings from the 1850s and 1860s.
The economy of Sacramento County is dominated by the government sector due to its status as the state capital, but it also has significant healthcare, education, and technology sectors.
Santa Clara County
Known as “Silicon Valley,” Santa Clara County is globally recognized as a hub for technology and innovation. The county’s cities of San Jose, Mountain View, and Palo Alto are home to many major tech companies like Apple, Google, and Facebook. In 2015, the area had the third-highest GDP per capita in the world.
San Jose is the county seat and largest city in Santa Clara County. It is the largest city in Northern California by population and area, and it’s the third-most populous in the state after Los Angeles and San Diego.
Santa Clara County was one of the original counties of California, formed at the time of statehood in 1850. The area was originally inhabited by the Ohlone, who subsisted by hunting, gathering, and harvesting.
More About California Counties
In which county is Silicon Valley?
Santa Clara County is commonly referred to as Silicon Valley because it is home to many high-tech companies and startups.
Which California county is most famous for wine production?
Napa County is globally renowned for its wine production, with a high concentration of world-class wineries and vineyards.
What is the poorest county in California?
Northern California’s Trinity County ranks as the poorest in the state with a typical household income of just over $40,000 per year.
Where is the most expensive place to live in California?
The most expensive places to live in California are Los Altos and Los Altos Hills. These are located in Santa Clara’s Silicon Valley, housing some of the most affluent business people in the area.
What county is Yosemite National Park located in?
Yosemite National Park is located in parts of Mariposa, Tuolumne, and Madera counties.