Imperial County, California

Imperial County is a county in California, United States, about 113 miles east of San Diego
across the Laguna Mountains. It had a population of 179,702 at the 2020 census, an estimated
180,202 by 2024, and covers 4,177 square miles (10,820 km2) of land centred near 33°04′N 115°35′W.

El Centro is the county seat and its largest city; its postal code is 92243. The county holds
7 incorporated cities and 9 unincorporated communities with no local government of their own,
and it runs on Pacific Time. Its FIPS code is 06025.

Towns & Villages in Imperial County

Imperial County has 16 named places on record: 7 incorporated cities and 9 census-designated
places (CDPs) with no elected municipal government of their own. California has no civil
townships, so the county administers all unincorporated land directly.

Three pairs on this list share a ZIP or a name pattern worth untangling. Desert Shores and
Salton Sea Beach both use 92274, though they sit on opposite sides of a small headland along the
Salton Sea’s western shore, 2.5 miles apart. Bombay Beach shares 92257 with Niland despite
lying roughly 20 miles south, on the Salton Sea’s eastern shore — it has never had its
own post office. And Westmorland is sometimes misspelled “Westmoreland”: the post
office briefly used that spelling from 1909 before the city settled on Westmorland in 1936.

ZIP Codes

• 92243 — El Centro
• 92231 — Calexico
• 92227 — Brawley
• 92251 — Imperial
• 92249 — Heber
• 92233 — Calipatria
• 92250 — Holtville
• 92275 — Salton City
• 92281 — Westmorland
• 92273 — Seeley
• 92274 — Desert Shores and Salton Sea Beach
• 92257 — Niland and Bombay Beach
• 92283 — Winterhaven
• 92259 — Ocotillo
• 92266 — Palo Verde

Bombay Beach and Salton Sea Beach have no post office of their own; both are served by rural
route delivery under a neighboring town’s ZIP.

Geography

Imperial County occupies the Imperial Valley, a low desert basin in California’s
southeastern corner that is part of the larger Colorado Desert. Much of the valley floor sits
below sea level, reclaimed for farming by Colorado River water carried through the All-American
Canal, which the Imperial Irrigation District uses to feed over 1,400 miles of canals and 1,100
miles of pipeline. The Salton Sea, California’s largest lake, covers the county’s
northern edge and lies about 235 feet below sea level at its shoreline; it formed in 1905–07
when floodwaters breached an irrigation channel from the Colorado River and filled the ancient
Salton Basin. The New River and Alamo River both flow north from Mexicali, across the border, into
the Salton Sea, carrying agricultural drainage along the way.

San Diego County borders Imperial to the west, Riverside County to the north, and Baja
California, Mexico, lies immediately south across the international line at Calexico and
Andrade. The Colorado River forms the eastern boundary with Yuma County, Arizona. San Diego County, Riverside County and Yuma County all border Imperial directly.

Demographics

Imperial County had a population of 179,702 at the 2020 census, and the latest estimate puts
the county near 180,202 residents as of 2024. El Centro and Calexico are by far the two largest
communities, together holding well over 40 percent of the county’s population. Median
household income runs $57,681, well below California’s statewide figure of $95,521 (2023
ACS) — among the widest gaps of any California county. Population density works out to
roughly 43 people per square mile of land, one of the lowest in Southern California, reflecting
the county’s vast irrigated farmland and desert open space outside its cities.

Economy & Local Life

Agriculture is the defining industry: Imperial Valley farms generate more than $1 billion in
crop value a year growing alfalfa, lettuce, sugar beets, carrots, cotton and grain, all irrigated
entirely by Colorado River water. Wikipedia’s Imperial Valley entry puts agriculture’s
share of regional employment at 48 percent, by far the largest of any sector. Away from the
fields, Health Care and Social Assistance employs the most workers on record at 10,391, followed
by Retail Trade at 6,966 and Public Administration at 6,240; two state prisons, Calipatria State
Prison and Centinela State Prison near Imperial, are major institutional employers, as is Naval
Air Facility El Centro, the Blue Angels’ winter training base since the 1950s. The
county’s biggest annual event is the California Mid-Winter Fair & Fiesta, held in
Imperial each late February and early March, drawing over 100,000 visitors.

History

California’s legislature formed Imperial County on 7 August 1907, carving it out of
eastern San Diego County. It was named for the Imperial Valley, itself named after the Imperial
Land Company, a subsidiary of the California Development Company that promoted the valley’s
irrigation and settlement around 1900. A 1905–07 breach in the company’s diversion
channel from the Colorado River flooded the desert basin for two years and created the Salton
Sea, before engineers closed the break and restored the river to its course.

Imperial was California’s first city in the valley to incorporate, in 1904, three years
before the county itself existed. On 4 April 2010, a magnitude 7.2 earthquake centred near
Mexicali struck the region, damaging buildings across El Centro and Calexico and prompting a
multi-year rebuilding effort.

Getting There

Interstate 8 crosses the county east–west, linking San Diego to Yuma, Arizona. State
Routes 86, 111, 78 and 98 connect the valley’s cities and the border crossings at Calexico
and Andrade.

• San Diego — about 113 miles west
• Yuma, Arizona — about 60 miles east
• Palm Springs — about 100 miles northwest
• Mexicali, Mexico — adjacent, across the border at Calexico

Imperial County Airport, on El Centro’s edge, has Essential Air Service flights to Los
Angeles and Phoenix on Southern Airways Express, but is mostly general aviation. San Diego
International Airport, about 113 miles west, is the nearest large hub. No Amtrak route serves the
county directly; the closest station is Yuma, Arizona, on the Sunset Limited line, about 60 miles
east.

Frequently Asked Questions

Where is Imperial County located?
It sits in California’s far southeastern corner, in the Imperial Valley, bordered by San
Diego and Riverside counties, Yuma County, Arizona, and Baja California, Mexico.

What is the population of Imperial County?
179,702 at the 2020 census, with a 2024 estimate near 180,202.

How big is Imperial County?
4,177 square miles (10,820 km2) of land, making it one of California’s larger counties by
area but one of its least densely populated.

What is the county seat of Imperial County?
El Centro, the county’s largest city, is the county seat.

How many towns and cities are in Imperial County?
Seven incorporated cities — El Centro, Calexico, Brawley, Imperial, Calipatria, Holtville
and Westmorland — plus nine census-designated places: Heber, Salton City, Seeley, Desert
Shores, Niland, Salton Sea Beach, Winterhaven, Ocotillo and Bombay Beach.

What ZIP codes does Imperial County use?
92243 for El Centro, 92231 for Calexico, 92227 for Brawley, 92251 for Imperial, and smaller codes
for each of the county’s other cities and CDPs, listed above.

What is Imperial County known for?
Winter vegetable farming fed entirely by Colorado River water, the below-sea-level Salton Sea, and
two international border crossings with Mexicali, Mexico, at Calexico.

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