Imperial County, California
|County of Imperial|
|Incorporated||August 7, 1907|
|Named for||Imperial Valley, which was named after the Imperial Land Company|
and largest city
|• Body||Board of Supervisors |
|• Chair||Ryan E. Kelley (N.P.)|
|• Vice Chair||Luis A. Plancarte (N.P.)|
|• Board of Supervisors|
|• Chief executive officer||Miguel Figueroa|
|• Total||4,482 sq mi (11,610 km2)|
|• Land||4,177 sq mi (10,820 km2)|
|• Water||305 sq mi (790 km2)|
|Highest elevation||4,551 ft (1,387 m)|
|Lowest elevation||−232 ft (−71 m)|
|• Density||43/sq mi (17/km2)|
|Time zone||UTC−8 (Pacific Time Zone)|
|• Summer (DST)||UTC−7 (Pacific Daylight Time)|
|GNIS feature ID||277277|
Imperial County (Spanish: Condado de Imperial) is a county located on the southeast border of the U.S. state of California. As of the 2020 census, the population was 179,702, making it 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 portions 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 3 inches (76 mm) 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 80% of the county's population is Hispanic, with the vast majority being of Mexican origin. The remainder of the population is predominantly non-Hispanic white, in addition to smaller African American, Native American, and Asian minorities.
This article needs additional citations for verification. (June 2009)
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, dispites 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 the 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 (Americans on the U.S. side, Mexicans on the other side) 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 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 1 mile (1.6 km) 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 100-mile (160 km) area.
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
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 3⁄8 mile (600 m).
Algodones Sand 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 40 miles (64 km) along the eastern edge of the Imperial Valley agricultural region in a band averaging 5 miles (8 km) 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.
The Colorado River streams through the southwestern United States and northwestern Mexico, approximately 1,450 miles (2,330 km) 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 (location ) 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
Anza-Borrego Desert State Park, portions of which are located in Imperial County, is the largest state park in California. 500 miles (800 km) 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.
The Imperial National Wildlife Refuge protects wildlife habitat along 30 miles (50 km) 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 40 miles (64 km) 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 227 feet (69 m) 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 100 °F (38 °C) with temperatures of 116–120 °F (47–49 °C) recorded yearly.
Museum of History in Granite
A unique attraction of the town of Felicity is the Museum of History in Granite. The museum exhibits granite monuments made from Missouri Red Granite. Each is 100 feet (30 m) 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.
According to the U.S. Census Bureau, the county has a total area of 4,482 square miles (11,610 km2), of which 4,177 square miles (10,820 km2) is land and 305 square miles (790 km2) (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.
The Colorado River forms the county's eastern boundary. Two notable geographic features are found in the county, the Salton Sea, at 235 feet (72 m) below sea level, and the Algodones Dunes, one of the largest dune fields in America.
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.
National protected areas
- Cibola National Wildlife Refuge (part)
- Imperial National Wildlife Refuge (part)
- Sonny Bono Salton Sea National Wildlife Refuge
|Population, race, and income|
|Black or African American||5,985||3.5%|
|American Indian or Alaska Native||3,020||1.8%|
|Native Hawaiian or other Pacific Islander||83||0.0%|
|Some other race||38,604||22.5%|
|Two or more races||5,398||3.2%|
|Hispanic or Latino (of any race)||136,376||79.6%|
|Per capita income||$16,593|
|Median household income||$39,402|
|Median family income||$43,769|
Places by population, race, and income
|Places by population and race|
|Asian||Black or African
|Hispanic or Latino|
(of any race)
|Salton Sea Beach||CDP||598||63.0%||10.2%||1.8%||0.0%||24.9%||53.8%|
|Places by population and income|
|Place||Type||Population||Per capita income||Median household income||Median family income|
|Salton Sea Beach||CDP||598||$17,791||$27,375||$57,159|
|U.S. Decennial Census|
The 2010 United States Census reported that Imperial County had a population of 174,528. The racial makeup of Imperial County was 102,553 (58.8%) White, 5,773 (3.3%) African American, 3,059 (1.8%) Native American, 2,843 (1.6%) Asian, 165 (0.1%) Pacific Islander, 52,413 (30.0%) from other races, and 7,722 (4.4%) from two or more races. Hispanic or Latino of any race were 140,271 persons (80.4%).
|Population reported at 2010 United States Census|
|Salton Sea Beach||422||309||6||4||2||2||82||17||229|
|All others not CDPs (combined)||24,343||15,683||1,849||1,546||355||26||4,059||825||14,877|
As of the census of 2000, there were 142,361 people, 39,384 households, and 31,467 families residing in the county. The population density was 34 people per square mile (13 people/km2). There were 43,891 housing units at an average density of 10 per square mile (3.9/km2). The racial makeup of the county was 49.4% White, 4.0% Black or African American, 1.9% Native American, 2.0% Asian, 0.1% Pacific Islander, 39.1% from other races, and 3.7% from two or more races. 72.2% of the population were Hispanic or Latino of any race. 65.7% spoke Spanish at home, while 32.3% spoke only English.
There were 39,384 households, out of which 46.7% had children under the age of 18 living with them, 57.7% were married couples living together, 17.1% had a female householder with no husband present, and 20.1% were non-families. 17.1% of all households were made up of individuals, and 8.1% had someone living alone who was 65 years of age or older. The average household size was 3.33 and the average family size was 3.77.
In the county, the population was spread out, with 31.4% under the age of 18, 9.9% from 18 to 24, 30.4% from 25 to 44, 18.2% from 45 to 64, and 10.0% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 109.3 males. For every 100 females age 18 and over, there were 111.4 males.
The median income for a household in the county was $31,870, and the median income for a family was $35,226. Males had a median income of $32,775 versus $23,974 for females. The per capita income for the county was $13,239. About 19.4% of families and 22.6% of the population were below the poverty line, including 28.7% of those under age 18 and 13.6% of those age 65 or over.
Imperial County has the lowest per capita income of any county in Southern California and among the bottom five counties in the state.
By 2006 the population had risen to 160,201, the population growth rate since the year 2000 was 30%, the highest in California and fifth highest in the United States in the time period. High levels of immigration, new residents search for affordable homes, and a search for retirement homes can explain the population increase.
The county is governed by the Imperial County Board of Supervisors, a five-member board elected by districts. Supervisors serve four-year terms. Other elected county officials include the Assessor, Auditor-Controller, District Attorney, County Clerk-Recorder, Public Administrator, Sheriff-Coroner, and Treasurer-Tax Collector. The county is run on a day-to-day basis by the County Executive Officer, who is currently Robin Hodgkin, on an interim basis. The county is advised as to legal matters by the County Counsel, who is currently Katherine K. Turner.
Voter registration statistics
|Population and registered voters|
|Registered voters[note 3]||60,690||35.4%|
|Peace and Freedom||255||0.4%|
|No party preference||13,299||21.9%|
Cities by population and voter registration
|Democratic||Republican||D–R spread||Other||No party preference|
Previously strongly Republican, Imperial County is now a Democratic stronghold in presidential, congressional and local elections. The last Republican to win a majority in the county was George H. W. Bush in 1988.
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.
Imperial County is in California's 25th congressional district, represented by Democrat Raul Ruiz. In the state legislature, the county is in the 56th Assembly District, represented by Democrat Lisa Calderon, and the 40th Senate District, represented by Republican Brian Jones.
The following table includes the number of incidents reported and the rate per 1,000 persons for each type of offense.
|Population and crime rates|
|Motor vehicle theft||940||5.49|
Cities by population and crime rates
|Cities by population and crime rates|
|City||Population||Violent crimes||Violent crime rate
per 1,000 persons
|Property crimes||Property crime rate|
per 1,000 persons
Thousands of acres of prime farmland have transformed the desert into one of the most productive farming regions in California with an annual crop production of over $1 billion. Agriculture is the largest industry in Imperial County and accounts for 48% of all employment. Although this region is a desert, with high temperatures and low average rainfall of 3 inches (76 mm) per year, the economy is heavily based on agriculture due to irrigation, which is supplied wholly from the Colorado River via the All-American Canal.
A vast system of canals, check dams, and pipelines carry the water all over the valley, a system which forms the Imperial Irrigation District, or IID. The water distribution system includes over 1,400 miles (2,300 km) of canal and with 1,100 miles (1,800 km) of pipeline. The number of canal and pipeline branches number roughly over a hundred. Imported water and a long growing season allow two crop cycles each year, and the Imperial Valley is a major source of winter fruits and vegetables, cotton, and grain for U.S. and international markets. Alfalfa is another major crop produced in the Imperial Valley. 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. Imperial County produces nearly 2/3 of all vegetables consumed by Americans during the winter.
A recent growth in the interest of Imperial County as a filming location, has spurred growth in servicing this industry. Because of the county's desert environment and proximity to Los Angeles, California, movies are sometimes filmed in the sand dunes outside the agricultural portions of the county. These have included Return of the Jedi, Stargate, The Scorpion King, and Into the Wild. Additionally, portions of the 2005 film Jarhead were filmed here because of its similarity to the desert terrain of Iraq.
In 2016, Imperial County had the highest unemployment rate of any county in the United States, at 23.5%.
Cotton in Imperial County and Riverside is predominantly Bt cotton.: Supplemental This is in contrast to the rest of the state, which largely relies on non-incorporated pesticides.: Supplemental The introduction of Bt cotton has dramatically reduced pesticide use here.: Supplemental
Renewable energy source
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. Much of the land suitable for green energy is owned by the federal government (Bureau of Land Management). As of April 2008, the BLM has received 163 applications to build renewable energy projects on 1,600,000 acres (6,500 km2) in California. Almost all of these are planned for the Imperial Valley and the desert region north of the valley. Stirling Energy is currently building one of the world's largest solar thermal plants, 10 square miles (26 km2) with 38,000 "sun catchers," it will power up to 600,000 homes once it is fully operational by around 2015. CalEnergy currently runs a geothermal plant that generates enough power for 300,000 homes and could tap into more for up to 2.5 million homes.
Imperial County is at the junction of one interstate, and three state highways. Radiating to the east and west are connections to the Arizona Sun Corridor and San Diego-Tijuana metropolitan area via Interstate 8, Blythe, and northern San Diego County via State Route 78, the Mexicali Valley via State Route 111, and the Coachella Valley, Inland Empire, and Los Angeles metropolitan area via State Route 86.
Imperial County is served by Greyhound Lines and Imperial Valley Transit buses. Through a partnership between Imperial County Transportation Commission (ICTC), the Yuma County Intergovernmental Public Transportation Authority (YCIPTA), and the Quechan Indian Tribe, Yuma County Area Transit buses serve portions of Imperial County and connects it to Yuma, Arizona. 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.
- 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 5 miles (8 km) east of Holtville.
- 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 15 miles (24 km) 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.
- 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.
- Fort Yuma Indian Reservation (partially in Yuma County, Arizona)
- Torres-Martinez Indian Reservation (partially in Riverside County)
† county seat
|Rank||City/Town/etc.||Municipal type||Population (2010 Census)|
|1||† El Centro||City||42,598|
|11||Fort Yuma Indian Reservation (partially in Yuma County, AZ)||AIAN||2,189|
|15||Salton Sea Beach||CDP||422|
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.
In popular culture
As a filming location
- Scenes for the 2006 film Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan were filmed in Imperial County, but were not used in the finished film.
- The majority of Jarhead and The Salton Sea were filmed in the Imperial Valley.
- Scenes from Top Gun were filmed at Naval Air Facility El Centro
- American Sniper was filmed in El Centro in fall 2014.
- Scenes from Jumanji: The Next Level were filmed in Imperial Dunes the spring of 2019.
- Part of Independence Day takes place in the Imperial Valley.
- Tucson-based indie rock band Calexico is named after Calexico.
- The 2009 nonfiction book Imperial by William T. Vollmann documents the history and culture of Imperial County. A companion volume of photographs was published August 18, 2009.
- The Sons of Anarchy spin-off Mayans MC takes place in Santo Padre, a fictional town in Imperial County.
- The video game Grand Theft Auto V features a county named Blaine County, which is based on Imperial County.
- In the 1963 film, It's a Mad, Mad, Mad, Mad World, Ethel Merman's character is heard talking on a phone to her son, saying that she was "in some place called Plaster City." Plaster City is an unincorporated community in Imperial County.
School districts are:
- 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
- Niland Geyser
- National Register of Historic Places listings in Imperial County, California
- Southern Border Region (California)
- Walters Camp
- Other = Some other race + Two or more races
- Native American = Native Hawaiian or other Pacific Islander + American Indian or Alaska Native
- Percentage of registered voters with respect to total population. Percentages of party members with respect to registered voters follow.
- "Jesus Eduardo Escobar, Supervisor, District 1 from Imperial County, California".
- "Luis A. Plancarte, Supervisor, District 2 from Imperial County, California".
- "Michael W. Kelley, Supervisor, District 3 from Imperial County, California".
- "Ryan e. Kelley, Supervisor, District 4 from Imperial County, California".
- "John Hawk Castillo, Supervisor, District 5 from Imperial County, California".
- "Blue Angels Peak". Peakbagger.com. Retrieved February 23, 2015.
- Southern shore of the Salton Sea
- "State & County QuickFacts". United States Census Bureau. Archived from the original on August 5, 2011. Retrieved April 4, 2016.
- "American FactFinder". Archived from the original on February 14, 2020. Retrieved April 19, 2019.
- "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
- [dead link]
- "Water Supply". Imperial Irrigation District. Retrieved April 20, 2023.
- "Water Transportation System". Imperial Irrigation District.
- "De Anza Trail". Solideas.com. Retrieved August 3, 2009.
- Naomi Sussman. “Indigenous Diplomacy and Spanish Mediation in the Lower Colorado-Gila River Region, 1771-1783.” Ethnohistory, vol. 66, no. 2, Apr. 2019, pp. 329–52. EBSCOhost, doi:10.1215/00141801-7298819.
- Thompson, D. Jerry (2006). Civil war to the bloody end: The life and times of Major General Samuel P. Heintzelman. San Antonio, Texas: Texas A&M University Press. ISBN 1-58544-535-5.
- "Tour Imperial Valley". CaliforniaResortLife. Archived from the original on December 22, 2015. Retrieved December 15, 2015.
- "This corner of California is suffering economic misery despite boom all around it". Los Angeles Times. February 5, 2019.
- "U.S. Census Bureau QuickFacts". Retrieved February 18, 2022.
- "Fort Yuma". Militarymuseum.org. Retrieved August 5, 2009.
- "Blue Angels Official Website". Blueangels.navy.mil. Archived from the original on April 30, 2009. Retrieved August 5, 2009.
- "2019 California Mid-Winter Fair and Fiesta opens Friday". The Desert Review. February 25, 2019. Retrieved April 1, 2019.
- "Imperial Valley Expo". Ivexpo.com. Archived from the original on June 14, 2009. Retrieved August 5, 2009.
- "Algodones Sand Dunes". Retrieved August 5, 2009.
- Rubio-Velázquez, Javier; Loaiciga, Hugo A.; Lopez-Carr, David (March 2, 2023). "Human-Induced Resource Scarcity in the Colorado River Basin and Its Implications for Water Supply and the Environment in the Mexicali Valley Transboundary Aquifer". Annals of the American Association of Geographers. 113 (5): 1172–1189. doi:10.1080/24694452.2022.2162477. S2CID 257326957. Retrieved April 20, 2023.
- "Things to Do in Yuma". Archived from the original on July 13, 2009. Retrieved August 5, 2009.
- "Tour Imperial Valley". CaliforniaResortLife. Archived from the original on December 22, 2015. Retrieved December 15, 2015.
- "Fossil Canyon and Painted Gorge". Retrieved August 5, 2009.
- "The Painted Gorge: From undersea to desert region". San Diego Reader. February 13, 2019. Retrieved November 11, 2022.
- "Imperial NWR". Archived from the original on June 12, 2009. Retrieved August 4, 2009.
- "Sonny Bono Salton Sea National Wildlife Refuge". Retrieved August 4, 2009.
- "2010 Census Gazetteer Files". United States Census Bureau. August 22, 2012. Retrieved September 26, 2015.
- "Imperial County". Archived from the original on May 2, 2014. Retrieved August 3, 2009.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B02001. U.S. Census website . Retrieved October 26, 2013.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B03003. U.S. Census website . Retrieved October 26, 2013.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B19301. U.S. Census website . Retrieved October 21, 2013.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B19013. U.S. Census website . Retrieved October 21, 2013.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B19113. U.S. Census website . Retrieved October 21, 2013.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates. U.S. Census website . Retrieved October 21, 2013.
- U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B01003. U.S. Census website . Retrieved October 21, 2013.
- Data unavailable
- "U.S. Decennial Census". United States Census Bureau. Retrieved September 26, 2015.
- "Historical Census Browser". University of Virginia Library. Retrieved September 26, 2015.
- Forstall, Richard L., ed. (March 27, 1995). "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Retrieved September 26, 2015.
- "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. April 2, 2001. Retrieved September 26, 2015.
- "2010 Census P.L. 94-171 Summary File Data". United States Census Bureau.
- "U.S. Census website". United States Census Bureau. Retrieved May 14, 2011.
- "Board of Supervisors". Co.imperial.ca.us. Archived from the original on May 2, 2014. Retrieved November 17, 2013.
- "Welcome to the Imperial County Assessor's Office". Archived from the original on May 29, 2016. Retrieved June 2, 2016.
- "County of Imperial - Auditor". Archived from the original on May 29, 2016. Retrieved June 2, 2016.
- "Home". Co.imperial.ca.us. Archived from the original on October 28, 2017. Retrieved November 7, 2017.
- website, Designed by Leonel Ibarra for The County of Imperial based on ca.gov. "Imperial County Clerk / Recorder Department". Co.imperial.ca.us. Archived from the original on November 7, 2017. Retrieved November 7, 2017.
- "Public AdministratorArea Agency on Aging". Public Administrator Area Agency on Aging. Archived from the original on October 22, 2017. Retrieved November 7, 2017.
- "Imperial County Sheriffs's Office". Icso.org. Retrieved November 7, 2017.
- "County of Imperial – TC – TR". Co.imperial.ca.us. Archived from the original on October 31, 2017. Retrieved November 7, 2017.
- "County Counsel – County of Imperial". Co.imperial.ca.us. Archived from the original on October 17, 2017. Retrieved November 7, 2017.
- "Board selects first woman to County Counsel". Retrieved November 7, 2017.
- California Secretary of State. February 10, 2013 – Report of Registration Archived July 27, 2013, at the Wayback Machine. Retrieved October 31, 2013.
- Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Retrieved November 7, 2017.
- "Proposition 8 Map – November 4, 2008, General Election – California Secretary of State". Sos.ca.gov. Archived from the original on August 8, 2009. Retrieved August 17, 2009.
- "Registration by County". Sos.ca.gov. Archived from the original on October 12, 2009. Retrieved August 17, 2009.
- Fagan, Kevin (August 26, 2010). "Imperial County steps up to defend Prop. 8". The San Francisco Chronicle. Archived from the original on August 25, 2010. Retrieved August 25, 2010.
- Denniston, Lyle (February 6, 2012). "Prop. 8: Final ruling due". SCOTUSblog. Retrieved June 18, 2013.
- "California's 25th Congressional District - Representatives & District Map". Civic Impulse, LLC. Retrieved April 7, 2013.
- "Members Assembly". State of California. Retrieved April 7, 2013.
- "Senators". State of California. Retrieved April 7, 2013.
- Office of the Attorney General, Department of Justice, State of California. Table 11: Crimes – 2009 Archived December 2, 2013, at the Wayback Machine. Retrieved November 14, 2013.
- Only larceny-theft cases involving property over $400 in value are reported as property crimes.
- United States Department of Justice, Federal Bureau of Investigation. Crime in the United States, 2012, Table 8 (California). Retrieved November 14, 2013.
- "El Centro Chamber of Commerce". Archived from the original on November 3, 2010. Retrieved August 3, 2009.
- Field Seeds, Grass Seeds, Forage, Hay, and Silage: 2017 and 2012 (PDF) (Report). US Department of Agriculture, National Agricultural Statistics Service. 2017. p. 8. Retrieved April 20, 2023.
- "IID". Archived from the original on June 3, 2009. Retrieved August 3, 2009.
- "Quick Facts About Imperial County Agriculture" (PDF). Imperial County Farm Bureau. Archived from the original (PDF) on February 18, 2018. Retrieved March 22, 2018.
- "Labor Force Data by County, 2016 Annual Averages". U.S. Bureau of Labor Statistics. Retrieved September 8, 2017.
- Epstein, Lynn; Bassein, Susan (2003). "Patterns of Pesticide Use in California and The Implications for Strategies for Reduction of Pesticides". Annual Review of Phytopathology. Annual Reviews. 41 (1): 351–375. doi:10.1146/annurev.phyto.41.052002.095612. ISSN 0066-4286. PMID 14527333.
- "Calif. Desert Becomes Home For Renewable Energy", Rob Schmitz, Morning Edition, April 3, 2009, NPR
- "Route connects El Centro, Yuma". schurz-ivpressonline. Archived from the original on December 20, 2016. Retrieved December 18, 2016.
- "ICTC/YCIPTA/Quechan Transit Services" (PDF). Imperialctc.org. Retrieved November 7, 2017.
- "2010 U.S. Census website". United States Census Bureau. Retrieved February 10, 2013.
- "2010 Census Interactive Population Search". Archived from the original on January 18, 2017. Retrieved December 7, 2017.
- [dead link]
- "2020 CENSUS - SCHOOL DISTRICT REFERENCE MAP: Imperial County, CA" (PDF). U.S. Census Bureau. Retrieved July 25, 2022. - Text list
- Official website
- Geographic data related to Imperial County, California at OpenStreetMap
- Imperial Irrigation District
- Imperial Valley Economic Development Corporation
- Statistical profile of Imperial County, California