Imperial County is located on the southeast border of the U.S. state of California. As of the 2020 census, the population was 179,702, ranking as the least populous county in Southern California. The county seat and largest city is El Centro. Imperial is the most recent California county to be established, as it was created in 1907 out of the eastern half of San Diego County.
Imperial County is located in the far southeast of California, in the Imperial Valley. It borders San Diego County to the west, Riverside County to the north, the U.S. state of Arizona to the east and the Mexican state of Baja California to the south. It includes the El Centro metropolitan statistical area and is part of the Southern California border region, the smallest but most economically diverse region in the state.
Although this region is a desert, with high temperatures and low average rainfall of per year, the economy is strongly based on agriculture. This is supported by irrigation, with water supplied wholly from the Colorado River via the All-American Canal.
The Imperial Valley straddles the border between the United States and Mexico. Imperial County is strongly influenced by Mexican culture. Approximately 85% of the county's population is Hispanic, with the vast majority being of Mexican origin. It has the highest proportion of Hispanics of any county in California. The remainder of the population is predominantly non-Hispanic white, in addition to smaller African American, Native American, and Asian minorities.
History
thumb|upright|left|[[Juan Bautista de Anza's noted expedition passed through the area in 1775.]]
The indigenous peoples of the area were the Quechan along the Colorado River, the Kamia-Kumeyaay west of the Quechan, and the Cahuilla to the north.
Spanish explorer Melchor Díaz was one of the first Europeans to visit the area of the Imperial Valley in 1540. The explorer Juan Bautista de Anza also explored the area in 1776. The indigenous peoples in the county were also engaged in an armed regional conflict, with the Quechan leading a coalition with the Kumeyaay against the Maricopa-led coalition with the Cahuilla, Cocopah, and other tribes in modern-day Arizona. Constant warfare would deny the Spanish explorers any overland access to Alta California, despite Spanish attempts to mediate the conflict.
Decades later, after the Mexican–American War, the northern half of the valley was annexed in 1848 by the U.S., while the southern half remained under Mexican rule.
Following the war, another war would consume the region in 1850 after the Glanton Gang sabotaged Quechan ferry operators and mugged a local Quechan chief. This would lead towards the start of the Yuma War, with a Quechan-led coalition of tribes against the US army and their indigenous allies in Baja California and Sonora. In the First Yuma War, the Quechan laid siege on Fort Yuma in 1851, and forced the American garrison there to abandon the fort. The Americans returned to the area in 1852 and subdued the Quechan by destroying their villages and farmland, and killed any warriors that resisted, leading to Quechan surrender to the US. The Second Yuma War would later see neighboring tribes erode much of the military advantages that the Quechan had left.
Small-scale settlement in natural aquifer areas had occurred in the early 19th century (the present-day site of Mexicali), but most permanent settlement was after 1900.
In 1905, torrential rainfall in the American Southwest caused the Colorado River (the only drainage for the region) to flood, including canals that had been built to irrigate the Imperial Valley. Since the valley is partially below sea level, the waters never fully receded, but collected in the Salton Sink in what is now called the Salton Sea.
Imperial County was formed in 1907 from the eastern portion of San Diego County. The county was named for Imperial Valley. This had been named for the Imperial Land Company, a subsidiary of the California Development Company, which at the turn of the 20th century had claimed the southern portion of the Colorado Desert for agriculture. The Imperial Land Company also owned extensive lands in Mexico (Baja California). Its objective was to develop commercial crop farming.
By 1910, the land company had managed to settle and develop thousands of farms on both sides of the border. The Mexican Revolution soon after severely disrupted the company's plans. Rival Mexican armies affiliated with different ethnicities killed nearly 10,000 farmers and their families in northern Mexico. Not until the 1920s was the other side of California in the United States sufficiently peaceful and prosperous for the company to earn a return for a large percentage of Mexicans. Some chose to stay and create roots in newly developed communities in the valley.
During the Great Depression and the Dust Bowl, the county attracted migrating "Okies" from drought-ridden farms on the plains by the need of migrant labor. More prosperous job-seekers also arrived from across the U.S. in the 1930s and 1940s. American entry into World War II stimulated the growth of jobs and need to expanded agriculture, and the All American Canal was completed from its source, the Colorado River, to Imperial Valley from 1948 to 1951. By the 1950 census, more than 50,000 residents lived in Imperial County alone, about 40 times the population of 1910. Most of the population was year-round, but would increase every winter by migrant laborers from Mexico. Until the 1960s, the farms in Imperial County provided substantial economic returns to the company and the valley.
During the Great Recession of 2008–11, El Centro had one of the highest unemployment rates (above 30–34%) in the U.S. In the early 2020s, Imperial ranks as one of California's poorest counties. It has a lower median household income than either the state or national medians.
Sites of interest
Fort Yuma
Fort Yuma is located on the banks of the Colorado River in Winterhaven, California. First established after the end of the Mexican–American War in 1848, it was originally located in the bottoms near the Colorado River, less than below the mouth of the Gila River. It was to defend the newly settled community of Yuma, Arizona, on the other side of the Colorado River and the nearby Mexican border. In March 1851 the post was moved to a small elevation on the Colorado's west bank, opposite the present city of Yuma, Arizona, on the site of the former Mission Puerto de Purísima Concepción. This site had been occupied by Camp Calhoun, named for John C. Calhoun, established in 1849. Fort Yuma was established to protect the southern emigrant travel route to California and to attempt control of the Yuma Indians in the surrounding area.
Blue Angels
right|thumb|Blue Angels
NAF El Centro is the winter home of the U.S. Navy Flight Demonstration Squadron, The Blue Angels. NAF El Centro historically kicks off the Blue Angels' season with their first air show, traditionally held in March.
Imperial Valley Expo & Fairgrounds
thumb|left|Mid-Winter Fair in Imperial, CA
The city of Imperial is home to the California Mid-Winter Fair and Fiesta which is the local county fair, held in late February to early March. It is also home to the Imperial Valley Speedway, a race track of .
Algodones Sand Dunes
thumb|right|The Algodones Dunes The name Algodones Dunes refers to the entire geographic feature, while the administrative designation for that portion managed by the Bureau of Land Management is the "Imperial Sand Dunes Recreation Area" (sometimes called the "Glamis Dunes"). The Algodones Sand Dunes are the largest mass of sand dunes in California. This dune system extends for more than along the eastern edge of the Imperial Valley agricultural region in a band averaging in width. A major east–west route of the Union Pacific railroad skirts the eastern edge. The dune system is divided into three areas. The northernmost area is known as Mammoth Wash. South of Mammoth Wash is the North Algodones Dunes Wilderness established by the 1994 California Desert Protection Act. This area is closed to motorized use and access is by hiking and horseback. The largest and most heavily used area begins at Highway 78 and continues south just past Interstate 8. The expansive dune formations offer picturesque scenery, a chance to view rare plants and animals, and a playground for ATV and off-roading enthusiasts. The dunes are also popular in film making and have been the site for movies such as Return of the Jedi.
Colorado River
The Colorado River streams through the southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The natural course of the river flows from north of Grand Lake, Colorado, into the Gulf of California. For many months out of the year, however, no water actually flows from the United States to the gulf, due to human use. The river is a popular destination for water sports, including fishing, boating, water skiing, and jet skiing.
Salvation Mountain
Salvation Mountain is an artificial mountain north of Calipatria, California, near Slab City. It is made from adobe, straw, and thousands of gallons of paint. It was created by Leonard Knight to convey the message that "God Loves Everyone". Knight refused substantial donations of money and labor from supporters who wished to modify his message of universal love to favor or disfavor particular groups.
Anza-Borrego Desert State Park
thumb|upright|right|Bighorn sheep at Palm Canyon in Anza-Borrego State Park
Anza-Borrego Desert State Park, portions of which are located in Imperial County, is the largest state park in California. of dirt roads, twelve wilderness areas, and many more miles of hiking trails provide visitors with an unparalleled opportunity to experience the wonders of the Colorado Desert. The park's name is a combination of the last name of Spanish explorer Juan Bautista de Anza, and the Spanish word for bighorn sheep, borrego. The park features many sweeping vistas, washes (wadis), rocky outcrops, boulder-strewn hillsides, in addition to the vast expanses of sandy desert; in springtime (especially after periods of rain), these areas appear to change shape, as they come alive with blooming wildflowers, flowering and fruiting cacti and numerous other species of native flora. Fauna that visitors may also have the chance to see include the bobcat, coyote, golden eagle, kit fox, mule deer, mountain lion, red-tailed hawk and roadrunner, as well as the iconic desert subspecies of bighorn sheep (formerly more common, across the southwest U.S. and northern Mexico). Many varied reptile species call the area home, such as the banded gecko, chuckwalla, desert iguana, desert tortoise, desert sidewinder, gopher snake, kingsnake, red diamond rattlesnake and the rosy boa.
Fossil Canyon and Painted Gorge
Located near Ocotillo, California in the Coyote Mountains, Fossil Canyon (and the surrounding area) is a great place for rock-hounding and fossil hunting. The fossils here are not necessarily of dinosaurs; more commonly found are ancient oyster and seashell, coral, and other marine life from the prehistoric Miocene epoch, when the entire area was submerged as part of the Western Interior Seaway.
The Painted Gorge, located on the eastern side of the Coyote Mountains, consists of sedimentary, metamorphic and igneous rock; Heat and movement over time has created fantastic shapes and colors. Dark ochre, iron-reds, royal purples, and mauves (mixed with dark browns/black) create a palette of color as the sun illuminates and plays shadows upon this geologic wonder.
Imperial NWR
thumb|right|Mesquite Point at Imperial NWR
The Imperial National Wildlife Refuge protects wildlife habitat along of the lower Colorado River in Arizona and California, including the last un-channeled section before the river enters Mexico. The river and its associated backwater lakes and wetlands are a green oasis, contrasting with the surrounding desert mountains. It is a refuge and breeding area for migratory birds and local desert wildlife.
Sonny Bono Salton Sea NWR
The Sonny Bono Salton Sea National Wildlife Refuge is located north of the Mexican border at the southern end of the Salton Sea in California's Imperial Valley. Situated along the Pacific Flyway, the refuge is the only one of its kind, located below sea level. Because of its southern latitude, elevation, and location in the Colorado Desert, the refuge experiences some of the highest temperatures in the nation. Daily temperatures from May to October generally exceed with temperatures of recorded yearly.
Museum of History in Granite
The Museum of History in Granite in the town of Felicity exhibits granite monuments made from Missouri Red Granite. Each is long. Subjects include a Korean War Memorial, History of Arizona, The Wall for the Ages, the eight monument History of Humanity, and the History of the United States of America. Smaller monuments include the Felicity Stone (sm), a Rosetta Stone for the future located at the center of the History of Humanity monuments.
Geography
thumb|Fields with Mount Signal in Background
According to the U.S. Census Bureau, the county has a total area of , of which is land and (6.8%) is water. Much of Imperial County is below sea level. Imperial County is roughly twice the size in total square miles as the State of Delaware.
Imperial county is bordered on the north by Riverside County; on the east by Yuma County, Arizona; on the south by Mexico; and on the west by San Diego County. The Colorado River forms the county's eastern boundary. Notable geographic features in the county include the Salton Sea, at below sea level, the Algodones Dunes, one of the largest dune fields in America, and Arturos Bridge, a natural arch.
The county is in the Colorado Desert, an extension of the larger Sonoran Desert. The Chocolate Mountains are located east of the Salton Sea, and extend in a northwest–southeast direction for approximately .
In this region, the geology is dominated by the transition of the tectonic plate boundary from rift to fault. The southernmost strands of the San Andreas Fault connect the northernmost extensions of the East Pacific Rise. Consequently, the region is subject to earthquakes, and the crust is being stretched, resulting in a sinking of the terrain over time. Related to the active geology are some interesting hydrothermal features. The area is also volcanic with multiple volcanic eruptions in the past few thousand years the most recent was 1,800 years ago.
National protected areas
- Cibola National Wildlife Refuge (part)
- Imperial National Wildlife Refuge (part)
- Sonny Bono Salton Sea National Wildlife Refuge
Demographics
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On November 4, 2008, Imperial County voted 69.7% for Proposition 8, which amended the California Constitution to ban same-sex marriages, showing more support for the proposition than any other strongly Democratic county. After Prop 8 was declared unconstitutional by a lower federal court, Imperial County continued to defend Proposition 8 in the federal judicial system. However, on February 6, 2012, the United States Court of Appeals for the Ninth Circuit denied Imperial County legal standing in the case Hollingsworth v. Perry.
In 2024, Imperial County also voted against 2024 California Proposition 3, which superseded Proposition 8, unlike its neighboring counties. However, the county voted for the unsuccessful 2024 California Proposition 32, which would have raised California's minimum wage to $18/hour, also unlike its neighboring counties. This indicates the county's political views are socially conservative, but economically progressive. The county voted for 2025 California Proposition 50, being one of several counties that voted for Donald Trump in 2024 to support the proposition.
Imperial County is in . In the state legislature, the county is in , and .
Crime
The following table includes the number of incidents reported and the rate per 1,000 persons for each type of offense.
{| class="wikitable collapsible collapsed"
|-
! colspan="3" | Population and crime rates
|-
! scope="row" style="text-align: left;" | Population
| 590 || 3.44
|-
! scope="row" style="text-align: left;" | Homicide
| 2,944 || 17.18
|-
! scope="row" style="text-align: left;" | Motor vehicle theft
! data-sort-type="number" | Violent crimes Imperial County produces nearly 2/3 of all vegetables consumed by Americans during the winter. The agricultural lands are served by a constructed agricultural drain system, which conveys surface runoff and subsurface drainage from fields to the Salton Sea, which is a designated repository for agricultural runoff.
Cotton in Imperial County and Riverside is predominantly Bt cotton.
El Centro is the commercial center of Imperial County. Fifty percent of the jobs in El Centro come from the service and retail sector.
The growth of Imperial County as a filming location has spurred growth in servicing this industry.
Renewable energy
Imperial Valley has become a hotbed of renewable energy projects, both solar and geothermal. This is driven in part by California's mandate to generate 20% of its power from renewable sources by the end of 2010, the valley's excellent sun resources, the high unemployment, its proximity to large population centers on the coast, and large tracts of otherwise unusable desert land. Amtrak trains on the Sunset Limited and Texas Eagle route also travel through the county, but with no scheduled stops; the nearest stop is in Yuma, Arizona.
Airports
County owned
- Imperial County Airport, the county's main airport, is primarily a general aviation facility. It is located just north of El Centro, and has limited commercial flight service subsidized by the Essential Air Service program.
- Holtville Airport is a public use general aviation airport, owned by the county and located roughly east of Holtville.
Municipal ownership
- Brawley Municipal Airport is a public use general aviation airport, owned by and located in Brawley.
- Calexico Airport is a public use general aviation field, owned by and located in Calexico. It is located south of Interstate 8 on State Route 111. It used in part to service maquiladora factories in nearby Mexicali.
- Cliff Hatfield Memorial Airport is a public use general aviation airport, owned by and located in Calipatria.
Privately owned
- Salton Sea Airport is a public use general aviation airport located in Salton City.
- Douthitt Strip Airport is a private use facility in El Centro. It was formerly a military airfield.
Military
- Naval Air Facility El Centro is a U.S. Navy airfield in El Centro.
Communities
Cities
- Brawley
- Calexico
- Calipatria
- El Centro (county seat)
- Holtville
- Imperial
- Westmorland
Census-designated places
- Bombay Beach
- Desert Shores
- El Centro NAF
- Heber
- Niland
- Ocotillo
- Palo Verde
- Salton Sea Beach
- Salton City
- Seeley
- Winterhaven
Unincorporated communities
- Alamorio
- Andrade
- Bard
- Bonds Corner
- Boulder Park
- Coyote Wells
- Dixieland
- Felicity
- Glamis
- Kane Spring
- Meloland
- Mount Signal
- Obregon
- Picacho
- Plaster City
- Slab City
Former settlements
- Bradtmoore
- Camp Gaston
- Carrizo Creek Station
- Hedges
- Indian Wells
- Jaeger City
- Ogilby
- Pilot Knob Station
- Potholes
- Sackett's Wells
- Silsbee
- Tumco
Indian Reservations
- Fort Yuma Indian Reservation (partially in Yuma County, Arizona)
- Torres-Martinez Indian Reservation (partially in Riverside County)
Population ranking
The population ranking of the following table is based on the 2010 census of Imperial County.
† county seat
{| class="wikitable sortable"
|-
!Rank
!City/Town/etc.
!Municipal type
!Population (2010 Census)
|- style="background-color:#FFFACD;"
| 1
|† El Centro
| City
| 42,598
|- style="background-color:#FFFACD;"
| 2
|Calexico
| City
| 38,572
|- style="background-color:#FFFACD;"
| 3
|Brawley
| City
| 24,953
|- style="background-color:#FFFACD;"
| 4
|Imperial
| City
| 14,758
|- style="background-color:#FFFACD;"
| 5
|Calipatria
| City
| 7,705
|- style="background-color:#FFFACD;"
| 6
|Holtville
| City
| 5,939
|- style="background-color:#FFFF99;"
| 7
|Torres-Martinez Reservation
| AIAN
| 5,594
|- style="background-color:#F0FFF0;"
| 8
|Heber
| CDP
| 4,275
|- style="background-color:#F0FFF0;"
| 9
|Salton City
| CDP
| 3,763
|- style="background-color:#FFFACD;"
| 10
|Westmorland
| City
| 2,225
|- style="background-color:#FFFF99;"
| 11
|Fort Yuma Indian Reservation (partially in Yuma County, AZ)
| AIAN
| 2,189
|- style="background-color:#F0FFF0;"
| 12
|Seeley
| CDP
| 1,739
|- style="background-color:#F0FFF0;"
| 13
|Desert Shores
| CDP
| 1,104
|- style="background-color:#F0FFF0;"
| 14
|Niland
| CDP
| 1,006
|- style="background-color:#F0FFF0;"
| 15
|Salton Sea Beach
| CDP
| 422
|- style="background-color:#F0FFF0;"
| 16
|Winterhaven
| CDP
| 394
|- style="background-color:#F0FFF0;"
| 17
|Bombay Beach
| CDP
| 295
|- style="background-color:#F0FFF0;"
| 18
|Ocotillo
| CDP
| 266
|- style="background-color:#F0FFF0;"
| 19
|Palo Verde
| CDP
| 171
|}
Area codes
442/760 – Covers all of the El Centro metropolitan area as well as Palm Springs, Oceanside, Bishop, Ridgecrest, Barstow, and Needles; northern San Diego County; and southeastern California, including much of the Mojave Desert and the Owens Valley. Area code 760 split from area code 619 on March 22, 1997, and was overlaid with area code 442 in 2009.
Education
School districts are:
Unified:
- Calexico Unified School District
- Calipatria Unified School District
- Coachella Valley Unified School District
- Holtville Unified School District
- Imperial Unified School District
- San Pasqual Valley Unified School District
Secondary:
- Brawley Union High School District
- Central Union High School District
Elementary:
- Brawley Elementary School District
- El Centro Elementary School District
- Heber Elementary School District
- Magnolia Union Elementary School District
- McCabe Union Elementary School District
- Meadows Union Elementary School District
- Mulberry Elementary School District
- Seeley Union Elementary School District
- Westmorland Union Elementary School District
See also
- Niland Geyser
- National Register of Historic Places listings in Imperial County, California
- Southern Border Region (California)
Notes
References
External links
- Imperial Irrigation District
- Imperial Valley Economic Development Corporation
- Statistical profile of Imperial County, California