San Bernardino County, California

San Bernardino County is a county in California, United States, stretching from the Los
Angeles metro area’s eastern edge across the Mojave Desert to the Nevada and Arizona
borders. It had a population of 2,181,654 at the 2020 census, an estimated 2,224,091 by 2025,
and covers 20,105 square miles (52,072 km2) centred near 34°50′N 116°11′W
— making it the largest county by area in the contiguous United States, bigger than each
of nine individual U.S. states.

San Bernardino is the county seat and its largest city; its postal code is 92401. The county
holds 24 incorporated cities and towns and dozens of unincorporated communities and census-
designated places, and it runs on Pacific Time. Its FIPS code is 06071.

Towns & Villages in San Bernardino County

All 24 incorporated cities and towns are listed below — 22 hold city charters and two,
Apple Valley and Yucca Valley, are legally towns. California has no civil townships, so the
table carries no Township column. A second table below covers the county’s largest
unincorporated communities and census-designated places (CDPs); the county has dozens more,
most under 3,000 residents, scattered across the mountain and desert regions.

Two pairs trip up mapping tools: Big Bear Lake (the incorporated city, population 5,046) sits
directly beside Big Bear City (an unincorporated CDP nearly three times larger, listed below) on
the lake’s east shore, and Apple Valley the town is distinct from Apple Valley Village, an
older name for part of the same town’s original townsite. Neither pair shares a boundary
with a same-named place in another county.

Largest Unincorporated Communities

The county’s CDPs outnumber its cities several times over; the 13 below are its largest
by 2020 census population, all in the Inland Empire foothills, the Victor Valley high desert, or
the San Bernardino Mountains.

Fort Irwin is the National Training Center, an active Army post; its CDP population counts
soldiers and families living on base rather than a conventional civilian town. Smaller named
places not tallied above — Landers, Morongo Valley, Homestead Valley, Silver Lakes, Yermo,
Baker, Helendale, Oak Hills, Running Springs and Trona among them — each hold under 5,700
residents.

ZIP Codes

ZIPs cluster into four bands. The Inland Empire cities in the southwest run roughly 91701
through 91786 (Rancho Cucamonga, Upland, Montclair, Chino, Chino Hills, Ontario) and 92313
through 92410 (San Bernardino 92401–92410 and 92418, Colton 92324, Redlands 92373–92374,
Highland 92346, Loma Linda 92354, Yucaipa 92399, Grand Terrace 92313). The Victor Valley high
desert uses 92301–92395 (Adelanto 92301, Apple Valley 92307–92308, Hesperia 92345,
Victorville 92392–92395, Spring Valley Lake 92395, Phelan 92371, Piñon Hills 92372).
The mountain resort towns share 92314–92397 (Big Bear Lake 92315, Big Bear City 92314,
Lake Arrowhead 92352, Crestline 92325, Wrightwood 92397, Running Springs 92382). The Mojave
Desert and Morongo Basin run 92277–92398 (Barstow 92311, Yermo 92398, Needles 92363,
Twentynine Palms 92277, Joshua Tree 92252, Yucca Valley 92284, Lucerne Valley 92356, Fort Irwin
92310). A handful of small mountain hamlets share their post office town’s ZIP rather than
carrying one of their own.

Geography

San Bernardino County spans three landscapes: the Inland Empire valley floor in the
southwest, the San Bernardino and San Gabriel Mountains across the middle, and the Mojave
Desert covering roughly 85 percent of the county’s land to the north and east. More than
80 percent of the county is federally owned — San Bernardino National Forest, Mojave
National Preserve, the Marine Corps Air Ground Combat Center at Twentynine Palms, Fort Irwin,
and parts of Death Valley and Joshua Tree National Parks all lie within its borders. The
Colorado River forms the county’s eastern edge with Arizona; Big Bear Lake, a reservoir in
the San Bernardino Mountains, is the county’s largest body of water.

San Bernardino County borders Los Angeles County to the west, Orange County at a short
southwestern corner, Riverside County to the south, Kern County to the northwest, and Inyo
County to the north, plus Clark County, Nevada, to the northeast and Mohave and La Paz counties,
Arizona, to the east. See the Los
Angeles County, Orange County,
Riverside County,
Kern County and
Inyo County pages for their own town
lists.

Demographics

The county had a population of 2,181,654 at the 2020 census and an estimated 2,224,091 by
2025, ranking it California’s fifth most populous county. San Bernardino (222,101) and
Fontana (208,407) are the largest communities, followed by Ontario and Rancho Cucamonga, both
over 174,000. Land-area density works out to roughly 109 people per square mile, though nearly
all residents live on the valley floor and in the Victor Valley — the desert interior is
sparsely populated. Median household income was $85,478 as of 2024 ACS estimates, below the
statewide figure; the poverty rate stood at 13.3 percent, above the national average.

Economy & Local Life

Health care and social assistance is the county’s largest employment sector at roughly
131,000 workers, followed by retail trade at about 120,000 and transportation and warehousing
at nearly 107,000 — the last reflecting the Inland Empire’s status as one of the
country’s largest logistics and distribution hubs, with Amazon and other fulfillment
centers concentrated around Fontana, Rialto and San Bernardino. Major named employers include
Stater Bros. Markets, headquartered in San Bernardino, Loma Linda University Medical Center,
Arrowhead Regional Medical Center in Colton, the San Manuel Band of Mission Indians’
Yaamava’ Resort & Casino in Highland, and Esri, the mapping-software company
headquartered in Redlands. Ontario International Airport also anchors a growing air-cargo
sector. The county’s largest annual event is the National Orange Show in San Bernardino,
held each May since 1915.

History

San Bernardino County was organized on April 26, 1853, carved from Los Angeles County. Its
name traces to 1810, when the Spanish missionary Francisco Dumetz named a native rancheria site
for St. Bernardino of Siena. Serrano, Cahuilla, Chemehuevi and Mohave communities lived across
the region long before Spanish contact; Mexican-era land grants created ranchos including
Rancho Cucamonga in the 1830s. Mormon settlers from Utah founded the city of San Bernardino in
1851, and the county’s desert towns — Barstow, Victorville, Needles — grew up
as railroad and, later, Route 66 stops in the early 20th century; Route 66 ran the length of the
county from Cajon Pass to the Colorado River, and its decline after Interstate 40 diverted
traffic left towns such as Amboy nearly empty. On December 2, 2015, a mass shooting at the
Inland Regional Center in San Bernardino killed 14 people at a county public-health training
event, one of the deadliest workplace attacks in recent U.S. history.

Getting There

Interstate 10 crosses the county’s southern cities, Interstate 15 runs northeast through
the Victor Valley toward Las Vegas, Interstate 40 crosses the Mojave Desert to Needles and
Arizona, and Interstate 215 links San Bernardino to Riverside County. State Route 66 (Historic
Route 66) still parallels I-40 and I-15 through Barstow, Victorville and Needles.

• Los Angeles — 60 miles west
• Riverside — 15 miles south
• Las Vegas — 160 miles northeast
• Palm Springs — 60 miles southeast

Ontario International Airport, in the city of Ontario, is the county’s main commercial
airport; San Bernardino International Airport handles cargo and general aviation. Amtrak’s
Southwest Chief stops at San Bernardino, Victorville and Barstow on its way to Needles and
Arizona; Metrolink commuter rail also serves San Bernardino, Rialto, Fontana, Rancho Cucamonga
and several other southern-county cities.

Frequently Asked Questions

Where is San Bernardino County?
It sits in southern California, bordering Los Angeles County to the west and stretching east to
the Nevada and Arizona state lines.

What is the population of San Bernardino County?
It had a population of 2,181,654 at the 2020 census, estimated at 2,224,091 by 2025.

How big is San Bernardino County?
It covers 20,105 square miles (52,072 km2), making it the largest county by area in the
contiguous United States — bigger than Rhode Island, Delaware and Connecticut combined,
several times over.

What is the county seat of San Bernardino County?
San Bernardino is the county seat, and its postal code is 92401.

How many towns and cities are in San Bernardino County?
The county has 24 incorporated cities and towns, plus dozens of unincorporated communities and
census-designated places such as Bloomington, Lake Arrowhead and Joshua Tree.

Which ZIP codes cover San Bernardino County?
ZIPs run from the low 91700s in the southwest Inland Empire cities to the 92200s–92400s
across the Victor Valley, mountain resort towns and Mojave Desert communities; see the ZIP Codes
section above for the full breakdown.

Is San Bernardino County the largest county in the United States?
It is the largest by area in the contiguous 48 states, though several Alaska boroughs, which
function similarly to counties, cover more ground.

More counties in this state: Towns
and villages in California.