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, 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 the eastern half of San Diego County.
The Santa Monica Mountains are a coastal mountain range in Southern California, next to the Pacific Ocean. It is part of the Transverse Ranges. The Santa Monica Mountains National Recreation Area encompasses this mountain range. Because of its proximity to densely populated regions, it is one of the most visited natural areas in California.
The Santa Rosa Mountains are a short mountain range in the Peninsular Ranges system, located east of the Los Angeles Basin and northeast of the San Diego metropolitan area of Southern California, in the Southwestern United States.
The Laguna Mountains are a mountain range of the Peninsular Ranges in eastern San Diego County, California. The mountains run in a northwest/southeast alignment for approximately 35 miles (56 km).
Palomar Mountain is a mountain ridge in the Peninsular Ranges in northern San Diego County, California. It is known as the location of Palomar Observatory and Hale Telescope, and known for Palomar Mountain State Park.
Cleveland National Forest is a U.S. national forest in Southern California that encompasses 460,000 acres/720 sq mi (1,900 km2) of inland montane regions. It is approximately 60 miles from the Pacific Ocean, within the counties of San Diego, Riverside, and Orange. The landscape varies somewhat, with mostly chaparral canyons, arroyos and high desert, but dotted with meadows and oak and conifer forests. Near water sources, riparian environments and perennial aquatic plants attract native and migratory wildlife, such as at San Diego’s man-made Lake Cuyamaca. A generally warm and dry, inland-Mediterranean climate prevails over the Forest, with the cooler months producing morning frost and snowfall. It is the southernmost U.S. National Forest of California. The area is administered by the U.S. Forest Service, a government agency within the United States Department of Agriculture, and is locally overseen by the Descanso, Palomar and Trabuco Ranger Districts.
The Dead Mountains are a mountain range in the southeastern Mojave Desert, in San Bernardino County, California. The range borders the tri-state intersection of Nevada, Arizona and California, and the Mohave Valley, with the Fort Mojave Indian Reservation bordering the range foothills on the east and northeast, in the three states.
The Jacumba Mountains are a mountain range of the Peninsular Ranges in eastern San Diego County, California, near the Mexico–United States border. The range reaches an elevation of 4,512 feet (1,375 m) at Jacumba Peak, near the southern end of the chain.
The Bigelow Cholla Garden Wilderness is in the eastern Mojave Desert and within Mojave Trails National Monument, located in San Bernardino County, California.
The Sweetwater River is a 55-mile (89 km) long stream in San Diego County, California. From its headwaters high in the Cuyamaca Mountains, the river flows generally southwest, first through rugged hinterlands but then into the urban areas surrounding its mouth at San Diego Bay. Its drainage basin covers more than 230 square miles (600 km2), all of it within San Diego County.
Cuyamaca Peak is a mountain peak of the Cuyamaca Mountains range in San Diego County, California.
Hot Springs Mountain is a peak in the Peninsular Ranges in San Diego County, California. The mountain rises to an elevation of 6,533 feet (1,991 m) and is the highest point in the county. Some snow falls on the mountain peak during winter. It is located in a remote region of the county, four miles from the community of Warner Springs, 12 miles from Borrego Springs, and 50 miles from San Diego. The mountain and its immediate surroundings belong to the Los Coyotes Band of Cahuilla and Cupeno Indians. The summit and fire tower can be hiked via the Sukat Road route from the campground. Hikers and campers must pay an entry fee to access the area.
Joshua Tree National Park is a national park of the United States in southeastern California, east of San Bernardino and Los Angeles and north of Palm Springs. It is named after the Joshua trees native to the Mojave Desert. Originally declared a national monument in 1936, Joshua Tree was redesignated as a national park in 1994 when the U.S. Congress passed the California Desert Protection Act. Encompassing a total of 795,156 acres – slightly larger than the state of Rhode Island – the park includes 429,690 acres of designated wilderness. Straddling San Bernardino and Riverside Counties, the park includes parts of two deserts, each an ecosystem whose characteristics are determined primarily by elevation: the higher Mojave Desert and the lower Colorado Desert. The Little San Bernardino Mountains traverse the southwest edge of the park.
The Coyote Mountains are a small mountain range in San Diego and Imperial County in Southern California. The Coyotes form a narrow ESE trending 2 mi (3.2 km) wide range with a length of about 12 mi (19 km). The southeast end turns and forms a 2 mi (3.2 km) north trending "hook". The highest point is Carrizo Mountain on the northeast end with an elevation of 2,408 feet (734 m). Mine Peak at the northwest end of the range has an elevation of 1,850 ft (560 m). Coyote Wash along Interstate 8 along the southeast margin of the range is 100 to 300 feet in elevation. Plaster City lies in the Yuha Desert about 5.5 mi (8.9 km) east of the east end of the range.
The San Felipe Hills are a low mountain range in eastern San Diego County, southern California.
Riverside County is a county located in the southern portion of the U.S. state of California. As of the 2020 census, the population was 2,418,185, making it the fourth-most populous county in California and the 10th-most populous in the United States. The name was derived from the city of Riverside, which is the county seat.
San Diego County, 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 Navy, Marine Corps, and Coast Guard in the county.
Los Coyotes Band of Cahuilla and Cupeño Indians of the Los Coyotes Reservation is a federally recognized tribe of Cahuilla and Cupeño Indians, who were Mission Indians located in California.
San Felipe Creek is a stream in Imperial and San Diego Counties of California. It arises in the Volcan Mountains of San Diego County 33°11′57″N116°37′35″W, and runs eastward, gathering the waters of most of the eastern slope of the mountains and desert of the county in the San Sebastian Marsh before it empties into the Salton Sea. It is probably the last remaining perennial natural desert stream in the Colorado Desert region. In 1974, the San Felipe Creek Area was designated as a National Natural Landmark by the National Park Service.
The 1968 Borrego Mountain earthquake occurred on April 8, at 18:28 PST in the geologically active Salton Trough of Southern California. The Salton Trough represents a pull-apart basin formed by movements along major faults. This region is dominated by major strike-slip faults one of them being the San Jacinto Fault which produced the 1968 earthquake. The mainshock's epicenter was near the unincorporated community of Ocotillo Wells in San Diego County. The moment magnitude (Mw ) 6.6 strike-slip earthquake struck with a focal depth of 11.1 km (6.9 mi). The zone of surface rupture was assigned a maximum Modified Mercalli intensity (MMI) of VII.
