California Counties. List Alphabetically (and by Population)
How many counties are there in California? As of 2024, there are a total of 58 counties in the state of California. Among them, Butte County is the oldest one (established in 1850) while Imperial County is the youngest (established in 1907). With population of 10,163,507, Los Angeles County is the most populated. The biggest county by land area is San Bernardino County (1853 km²) and the smallest is San Francisco (122 km²).
Largest Counties in California
1. San Bernardino County
County Seat: San Bernardino
- Area: 20,105 square miles
- Population: Approximately 2,180,085 (2020 census)
- Area Codes: 909, 760, 442
- Latitude: 34.1083° N
- Longitude: 117.2898° W
Location and History
San Bernardino County is the largest county in the United States by area, located in the southeastern part of California. It was established on April 26, 1853, and named after the Spanish mission San Bernardino de Sena Estancia, which was named for Saint Bernardino of Siena. The county’s diverse geography ranges from the Mojave Desert to the San Bernardino Mountains, offering a mix of arid desert landscapes and lush forests. The development of the county was heavily influenced by the Southern Pacific Railroad and the establishment of Route 66, both of which facilitated growth and connectivity in the region.
Major Highways and Landmarks
San Bernardino County is served by several major highways, including Interstates 10, 15, and 40, which connect it to Los Angeles, Las Vegas, and other major cities. U.S. Routes 95 and 395 also traverse the county. Notable landmarks include Joshua Tree National Park, known for its unique desert flora and rock formations, and the San Bernardino National Forest, which offers a range of outdoor activities. The county is also home to the historic Route 66, with several attractions and museums dedicated to the iconic highway. Additionally, Big Bear Lake is a popular destination for skiing, boating, and hiking.
2. Inyo County
County Seat: Independence
- Area: 10,192 square miles
- Population: Approximately 19,016 (2020 census)
- Area Codes: 760, 442
- Latitude: 36.8023° N
- Longitude: 118.2000° W
Location and History
Inyo County is located in the eastern part of California, encompassing a large portion of the Eastern Sierra Nevada and the Owens Valley. It was established on March 22, 1866, and the name “Inyo” is derived from the Native American Paiute word meaning “dwelling place of the great spirit.” The county’s history is deeply connected to mining, particularly during the California Gold Rush, and later to the controversial Los Angeles Aqueduct, which diverted water from the Owens Valley to Los Angeles. The region is known for its extreme geographical features, including the highest and lowest points in the contiguous United States: Mount Whitney and Badwater Basin in Death Valley.
Major Highways and Landmarks
Inyo County is served by U.S. Route 395, which runs north-south along the Sierra Nevada, and State Route 136, which connects to Death Valley National Park. Key landmarks include Death Valley National Park, known for its stunning and harsh desert landscapes, and Mount Whitney, the highest peak in the contiguous United States. The Ancient Bristlecone Pine Forest, home to some of the oldest trees on Earth, is another significant site. The Manzanar National Historic Site, a former Japanese internment camp during World War II, offers a poignant reminder of the county’s complex history.
3. Kern County
County Seat: Bakersfield
- Area: 8,161 square miles
- Population: Approximately 909,235 (2020 census)
- Area Codes: 661
- Latitude: 35.3733° N
- Longitude: 119.0187° W
Location and History
Kern County is located in the southern part of California’s Central Valley, extending into the Sierra Nevada and the Mojave Desert. The county was established on April 2, 1866, and named after the Kern River, which was itself named by explorer John C. Frémont after Edward Kern, his cartographer. Bakersfield, the county seat, grew rapidly due to the discovery of oil in the early 20th century, making Kern County one of the leading oil-producing regions in the United States. Agriculture, particularly cotton, citrus, and nuts, also plays a significant role in the county’s economy.
Major Highways and Landmarks
Kern County is served by major highways such as Interstate 5, which runs along the western edge of the county, and U.S. Routes 58, 99, and 395, which provide key connections within the state. Significant landmarks include the Tehachapi Loop, an engineering marvel on the Union Pacific Railroad, and the Kern River Canyon, known for its stunning views and whitewater rafting opportunities. The county is also home to the California Living Museum (CALM), a zoo and botanical garden dedicated to native California species. Additionally, Edwards Air Force Base, located in the Mojave Desert, is a significant military and aerospace testing site.
4. Riverside County
County Seat: Riverside
- Area: 7,303 square miles
- Population: Approximately 2,418,185 (2020 census)
- Area Codes: 951, 760, 442
- Latitude: 33.9533° N
- Longitude: 117.3962° W
Location and History
Riverside County is located in southern California, stretching from the Greater Los Angeles area to the Arizona border. The county was established on May 9, 1893, and was named for the city of Riverside, which was founded as a colony for citrus cultivation. The county’s history is closely tied to agriculture, particularly the citrus industry, which played a crucial role in California’s economic development in the late 19th and early 20th centuries. Riverside County’s diverse geography includes mountains, deserts, and fertile valleys, making it a region of both natural beauty and agricultural productivity.
Major Highways and Landmarks
Riverside County is served by several major highways, including Interstates 10, 15, and 215, as well as U.S. Routes 60 and 95. Key landmarks include Joshua Tree National Park, famous for its unique Joshua trees and dramatic desert landscapes, and the Coachella Valley, known for its music and arts festival as well as luxurious resorts in cities like Palm Springs. The county also includes Lake Perris State Recreation Area, a popular destination for boating, fishing, and camping. Additionally, the historic Mission Inn in downtown Riverside is a significant cultural and architectural landmark.
5. Siskiyou County
County Seat: Yreka
- Area: 6,347 square miles
- Population: Approximately 44,076 (2020 census)
- Area Codes: 530
- Latitude: 41.7350° N
- Longitude: 122.6346° W
Location and History
Siskiyou County is located in the northernmost part of California, bordering Oregon. The county was established on March 22, 1852, and its name is believed to be derived from a Native American word, although its exact meaning is unclear. Yreka, the county seat, became a key town during the California Gold Rush, attracting miners and settlers to the area. The county’s history is closely tied to mining, timber, and later, agriculture. Siskiyou County is known for its rugged terrain, including the Klamath Mountains and Mount Shasta, one of the most iconic peaks in California.
Major Highways and Landmarks
Siskiyou County is traversed by Interstate 5, which provides a major north-south route through the region, and U.S. Routes 97 and 96. Key landmarks include Mount Shasta, a towering volcano that offers hiking, skiing, and spiritual retreats. The county is also home to Lava Beds National Monument, known for its extensive lava tube caves and Native American rock art. The Klamath National Forest and the Marble Mountains provide additional opportunities for outdoor recreation, including camping, fishing, and backpacking. Yreka’s historic downtown, with its well-preserved 19th-century buildings, reflects the county’s Gold Rush heritage.
6. Fresno County
County Seat: Fresno
- Area: 6,011 square miles
- Population: Approximately 1,008,654 (2020 census)
- Area Codes: 559
- Latitude: 36.7378° N
- Longitude: 119.7871° W
Location and History
Fresno County is located in the central part of California, within the fertile San Joaquin Valley. It was established on April 19, 1856, and named after the abundant ash trees (“fresno” in Spanish) that grow along the Fresno River. The county seat, Fresno, grew from a small railroad station into the fifth-largest city in California, largely due to the development of agriculture in the region. Fresno County is one of the most productive agricultural regions in the United States, producing a significant portion of the nation’s fruits, vegetables, and nuts.
Major Highways and Landmarks
Fresno County is served by major highways including Interstate 5 and U.S. Route 99, which run north-south through the county, and State Routes 41 and 180. Significant landmarks include Yosemite National Park, part of which lies within Fresno County and offers world-renowned natural beauty, including waterfalls, giant sequoias, and granite cliffs. The county is also home to the Forestiere Underground Gardens, an intricate network of subterranean rooms and tunnels built by a Sicilian immigrant. The Fresno Chaffee Zoo and Woodward Park in Fresno are popular destinations for families and outdoor enthusiasts.
7. Tulare County
County Seat: Visalia
- Area: 4,839 square miles
- Population: Approximately 473,117 (2020 census)
- Area Codes: 559
- Latitude: 36.3302° N
- Longitude: 119.2921° W
Location and History
Tulare County is located in the southern part of California’s Central Valley, adjacent to the Sierra Nevada mountains. The county was established on April 20, 1852, and named after Tulare Lake, which was once the largest freshwater lake west of the Mississippi River before it dried up due to agricultural diversion. Visalia, the county seat, is one of the oldest towns in the San Joaquin Valley, with a history rooted in agriculture and cattle ranching. The county’s economy continues to be dominated by agriculture, particularly dairy farming, citrus, and nuts.
Major Highways and Landmarks
Tulare County is served by major highways including U.S. Route 99, which runs through the county, and State Routes 198 and 65. Significant landmarks include Sequoia and Kings Canyon National Parks, home to some of the largest trees in the world, including the famous General Sherman Tree. The Sierra Nevada mountains offer numerous opportunities for outdoor activities such as hiking, camping, and skiing. The county is also known for its vibrant agricultural festivals, such as the Tulare County Fair and the World Ag Expo, one of the largest agricultural trade shows in the world.
8. Lassen County
County Seat: Susanville
- Area: 4,720 square miles
- Population: Approximately 30,573 (2020 census)
- Area Codes: 530
- Latitude: 40.4163° N
- Longitude: 120.6530° W
Location and History
Lassen County is located in northeastern California, bordered by Nevada to the east. It was established on April 1, 1864, and named after Peter Lassen, a Danish immigrant and pioneer who played a key role in the early settlement of the region. Susanville, the county seat, grew as a lumber town and later as a center for government services. The county’s history is marked by its remote location and rugged terrain, which have made it a haven for outdoor enthusiasts. Lassen County is characterized by its mix of forests, lakes, and high desert landscapes.
Major Highways and Landmarks
Lassen County is served by U.S. Route 395, which runs north-south through the county, and State Route 36. Key landmarks include Lassen Volcanic National Park, which features geothermal wonders such as hot springs, fumaroles, and the active Lassen Peak volcano. Eagle Lake, the second-largest natural lake entirely within California, is another popular destination for fishing, boating, and camping. The county also includes portions of the Lassen National Forest, offering miles of trails and scenic vistas. The historic Susanville Railroad Depot and the Lassen Historical Museum provide insights into the county’s pioneer past.
9. Modoc County
County Seat: Alturas
- Area: 4,203 square miles
- Population: Approximately 8,700 (2020 census)
- Area Codes: 530
- Latitude: 41.4877° N
- Longitude: 120.5426° W
Location and History
Modoc County is located in the northeastern corner of California, bordering Oregon and Nevada. The county was established on February 17, 1874, and named after the Modoc people, a Native American tribe that historically inhabited the region. The county seat, Alturas, developed as a ranching and trading center in the late 19th century. Modoc County’s history is marked by its rugged landscape and remote location, which have kept it sparsely populated. The county’s economy has traditionally been based on agriculture, forestry, and mining.
Major Highways and Landmarks
Modoc County is accessible via U.S. Route 395 and State Routes 299 and 139. Significant landmarks include the Modoc National Forest, which offers a diverse range of ecosystems from high desert to alpine forests, and the Lava Beds National Monument, known for its extensive lava tube caves and Native American petroglyphs. The county is also home to Goose Lake, which straddles the California-Oregon border and provides opportunities for birdwatching, fishing, and boating. The Warner Mountains, with their scenic beauty and outdoor recreation opportunities, are another key feature of the county.
10. Mono County
County Seat: Bridgeport
- Area: 3,132 square miles
- Population: Approximately 14,444 (2020 census)
- Area Codes: 760, 442
- Latitude: 38.2550° N
- Longitude: 119.2348° W
Location and History
Mono County is located in the eastern Sierra Nevada region of California, bordered by Nevada to the east. The county was established on April 24, 1861, and named after Mono Lake, a large saline lake that is one of the oldest lakes in North America. Bridgeport, the county seat, developed as a supply center for miners and ranchers in the 19th century. The county’s history is deeply tied to its natural environment, with the Eastern Sierra serving as a major draw for outdoor enthusiasts, photographers, and tourists.
Major Highways and Landmarks
Mono County is served by U.S. Route 395, which runs along the eastern edge of the Sierra Nevada and connects many of the county’s key towns and attractions. Key landmarks include Mono Lake, known for its striking tufa towers and unique ecosystem, and the Mammoth Mountain ski area, one of California’s premier destinations for winter sports. The county also includes portions of the Yosemite National Park and the Ansel Adams Wilderness, offering some of the most breathtaking mountain scenery in the state. Bodie State Historic Park, a well-preserved ghost town, provides a glimpse into the county’s Gold Rush past.
List of All Counties in California Alphabetically
Below please see all California counties which are listed in alphabetical order.
- Alameda County, CA
- Alpine County, CA
- Amador County, CA
- Butte County, CA
- Calaveras County, CA
- Colusa County, CA
- Contra Costa County, CA
- Del Norte County, CA
- El Dorado County, CA
- Fresno County, CA
- Glenn County, CA
- Humboldt County, CA
- Imperial County, CA
- Inyo County, CA
- Kern County, CA
- Kings County, CA
- Lake County, CA
- Lassen County, CA
- Los Angeles County, CA
- Madera County, CA
- Marin County, CA
- Mariposa County, CA
- Mendocino County, CA
- Merced County, CA
- Modoc County, CA
- Mono County, CA
- Monterey County, CA
- Napa County, CA
- Nevada County, CA
- Orange County, CA
- Placer County, CA
- Plumas County, CA
- Riverside County, CA
- Sacramento County, CA
- San Benito County, CA
- San Bernardino County, CA
- San Diego County, CA
- The City and County of San Francisco, CA
- San Joaquin County, CA
- San Luis Obispo County, CA
- San Mateo County, CA
- Santa Barbara County, CA
- Santa Clara County, CA
- Santa Cruz County, CA
- Shasta County, CA
- Sierra County, CA
- Siskiyou County, CA
- Solano County, CA
- Sonoma County, CA
- Stanislaus County, CA
- Sutter County, CA
- Tehama County, CA
- Trinity County, CA
- Tulare County, CA
- Tuolumne County, CA
- Ventura County, CA
- Yolo County, CA
- Yuba County, CA
Map of California Counties
