33°44′N 115°59′W / 33.73°N 115.98°W
Riverside County is a county in the U.S. state of California. As of the 2020 census, its population was 2,418,185, making it the fourth-most populous county in California and the 10th-most populous in the United States. Located in Southern California, the county is named for the city of Riverside, which is its county seat.
The Salton Sea is a shallow, landlocked, highly saline endorheic lake in Riverside and Imperial counties in Southern California. It lies on the San Andreas Fault within the Salton Trough, which stretches to the Gulf of California in Mexico. The lake is about 15 by 35 miles (24 by 56 km) at its widest and longest. A 2023 report put the surface area at 318 square miles (823.6 km). The Salton Sea became a resort destination in the 20th century, but saw die-offs of fish and birds in the 1980s due to contamination from farm runoff, and clouds of toxic dust in the current century as evaporation exposed parts of the lake bed.
Over millions of years, the Colorado River had flowed into the Imperial Valley and deposited alluvium (soil), creating fertile farmland, building up the terrain, and constantly moving its main course and river delta. For thousands of years, the river alternately flowed into the valley or diverted around it, creating either a salt lake called Lake Cahuilla or a dry desert basin, respectively. When the river diverted around the valley, the lake dried completely, as it did around 1580. Hundreds of archaeological sites have been found in this region, indicating possibly long-term Native American villages and temporary camps.
Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal region includes Greater Los Angeles (the second-most populous urban agglomeration in the United States) and San Diego County (the second-most populous county in California). The region generally contains ten of California's 58 counties: Los Angeles, San Diego, Orange, Riverside, San Bernardino, Kern, Ventura, Santa Barbara, San Luis Obispo, and Imperial counties.
Although geographically smaller than Northern California in land area, Southern California has a higher population, with 23.76 million residents as of the 2020 census. The sparsely populated desert region of California occupies a significant portion of the area: the Colorado Desert, along with the Colorado River, is located on Southern California's eastern border with Arizona, and the Mojave Desert shares a border with Nevada to the northeast. Southern California's southern border with Baja California is part of the Mexico–United States border.
The Inland Empire (commonly abbreviated as the IE) is a metropolitan area and region inland of and adjacent to coastal Southern California in the Greater Los Angeles area, focusing around the cities in Riverside and San Bernardino county with Los Angeles County and Orange County to the west. The region, at its narrowest definition, includes the cities of northwestern Riverside County and southwestern San Bernardino County that are part of the contiguous urbanized area of Greater Los Angeles. It is sometimes considered to include the desert communities of the Coachella and Victor Valleys, respectively on the other sides of the San Gorgonio Pass and San Bernardino Mountains from the Santa Ana River watershed that creates the majority of the Inland Empire. A much wider definition includes the entireties of Riverside and San Bernardino counties, stretching east to the Nevada and Arizona borders and covering a larger area than West Virginia; this definition is primarily used by the US Census Bureau, which exclusively delineates metropolitan areas at the county level.
The U.S. Census Bureau–defined Riverside–San Bernardino–Ontario metropolitan area, which comprises Riverside County and San Bernardino, California, covers more than 27,000 sq mi (70,000 km) and had a population of about 4.6 million in 2020. At the end of the 19th century, the Inland Empire was a major center of agriculture, including citrus, dairy and winemaking. Agriculture declined through the 20th century and a rapidly increasing population, helped by families migrating in search of affordable housing, has led to more residential, industrial and commercial development since the 1970s.
The San Gorgonio Pass wind farm is a wind farm that stretches from the eastern slope of the San Gorgonio Pass, near Cabazon, to North Palm Springs, on the western end of the Coachella Valley, in Riverside County, California. Flanked by Mount San Gorgonio and the Transverse Ranges to the North, and Mount San Jacinto and the Peninsular Ranges to the South, the San Gorgonio Pass is a transitional zone from a Mediterranean climate west of the pass, to a Desert climate east of the pass. This makes the pass area one of the most consistently windy places in the United States.
Development of the wind farm began in the 1980s. It is one of the first three major wind farm areas in California, along with those at Altamont and the Tehachapi passes.
San Diego County (/ˌsæn diˈeɪɡoʊ/ ), officially the County of San Diego, is a county in the southwest corner of the U.S. state of California, north to its border with Mexico. As of the 2020 census, the population was 3,298,634; it is the second-most populous county in California and the fifth-most populous in the United States. Its county seat is San Diego, the second-most populous city in California and the eighth-most populous in the United States. It is the southwesternmost county in the 48 contiguous United States, and is a border county. It is home to 18 Indian reservations, the most of any county in the United States. There are 16 military installations of the U.S. Navy, Marine Corps, and Coast Guard in the county.
San Diego County comprises the San Diego–Chula Vista–Carlsbad, CA Metropolitan Statistical Area, which is the 18th most populous metropolitan statistical area and the 18th most populous primary statistical area in the United States. San Diego County is also part of the San Diego–Tijuana region, the largest metropolitan area shared between the United States and Mexico. From north to south, San Diego County extends from the southern borders of Orange and Riverside counties to the Mexico–U.S. border and the municipalities of Tijuana and Tecate in Baja California. From west to east, San Diego County stretches from the Pacific Ocean to its boundary with Imperial County, which separated from it in 1907.
Imperial County 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, 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.
Anza-Borrego Desert State Park (/ˈænzə bəˈreɪɡoʊ/, AN-zə bə-RAY-goh) is a California State Park located within the Colorado Desert of Southern California, United States. Created in 1932, the park takes its name from 18th century Spanish explorer Juan Bautista de Anza and borrego, a Spanish word for sheep. With 650,000 acres (260,000 ha) that includes one-fifth of San Diego County, it is the largest state park in California and the third largest state park nationally.
The park occupies eastern San Diego County and reaches into Imperial and Riverside counties, enveloping two communities: Borrego Springs, which is home to the park's headquarters, and Shelter Valley.