California's Colorado Desert is a part of the larger Sonoran Desert. It encompasses 7 million acres, including the irrigated Coachella and Imperial valleys, it is home to fauna. The Colorado Desert is a subdivision of the larger Sonoran Desert encompassing 7 million acres; the desert encompasses Imperial County and includes parts of San Diego County, Riverside County, a small part of San Bernardino County. Most of the Colorado Desert lies at a low elevation, below 1,000 feet, with the lowest point of the desert floor at 275 feet below sea level, at the Salton Sea. Although the highest peaks of the Peninsular Ranges reach elevations of nearly 10,000 feet, most of the region's mountains do not exceed 3,000 feet. 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 to the northernmost extensions of the East Pacific Rise. The region is subject to earthquakes, the crust is being stretched, which will result in a sinking of the terrain over time.
The Colorado Desert's climate distinguishes it from other deserts. The region experiences greater summer daytime temperatures than higher-elevation deserts and never experiences frost. In addition, the Colorado Desert experiences two rainy seasons per year toward the southern portion of the region; the west coast Peninsular Ranges, or other west ranges, of Southern California–northern Baja California, block most eastern Pacific coastal air and rains, producing an arid climate. Other short or longer-term weather events can move in from the Gulf of California to the south, are active in the summer monsoons; these include remnants of Pacific hurricanes, storms from the southern tropical jetstream, the northern intertropical convergence zone. The region's terrestrial habitats include creosote bush scrub. Higher elevations are dominated by pinyon pine and California juniper, with areas of manzanita and Coulter pine. In addition to hardy perennials, more than half of the desert's plant species are herbaceous annuals, appropriately timed winter rains produce abundant early spring wildflowers.
In the southern portion of the region, the additional moisture supplied by summer rainfall fosters the germination of summer annual plants and supports smoketree and palo verde trees. Common desert wildlife include mule deer, desert kangaroo rat, cactus mouse, black-tailed jackrabbit, Gambel's quail, red-diamond rattlesnake. Among sensitive species are flat-tailed horned lizard, Coachella Valley fringe-toed lizard, desert tortoise, prairie falcon, Andrews' dune scarab beetle, peninsular bighorn sheep, California leaf-nosed bat; the best place to spot wildlife is at the wetland refuges along the Colorado River, Cibola National Wildlife Refuge and Imperial National Wildlife Refuge. In the Colorado Desert's arid environment and wetland habitats are limited in extent but are critically important to wildlife. Runoff from seasonal rains and groundwater springs forms desert arroyos, desert fan palm oases, freshwater marshes, brine lakes, desert washes and perennial streams, desert riparian vegetation communities dominated by cottonwood and non-native tamarisk.
Two of the region's most significant aquatic systems are the Colorado River. While most desert wildlife depend on aquatic habitats as water sources, a number of species, such as the arroyo toad, desert pupfish, Yuma rail, southwestern willow flycatcher, are restricted to these habitats. In some places, summer rains produce short-lived seasonal pools that host uncommon species like Couch's spadefoot toad. Desert fan palm oases are rare, they occur only where permanent water sources are available, such as at springs or along fault lines, where groundwater is forced to the surface by the movement of hard impermeable rock, can be found in the San Jacinto, Santa Rosa, Little San Bernardino mountains, in the canyons of Anza-Borrego Desert State Park, along the San Andreas Fault in the Coachella Valley. The only palm native to California, Washingtonia filifera, grows at the oases; some sub-regions of the Colorado Desert contain endemic flora. Along the Lower Colorado River Valley, in-flow side canyons, flatlands, or low-to-higher level elevations, at least three such flora occur: Hesperocallis undulata, Nolina bigelovii, Peucephyllum schottii.
Joshua Tree National Park Imperial NWR Sonny Bono Salton Sea NWR Indio Hills Palms Anza-Borrego Desert State Park Ocotillo Wells State Vehicular Recreation Area Picacho State Recreation Area Heber Dunes State Vehicular Recreation Area Salton Sea State Recreation Area The Colorado Desert is one of the least-populous regions in California, but human activities have had substantial impacts on the region's habitats and wildlife. Many unique communities aquatic and dune systems, are limited in distribution and separated by vast expanses of inhospitable, arid desert terrain. Limited human disturbances can have markedly deleterious effects on the endemic and sensitive species supported by these unique regional systems; some of the greatest human-caused effects on the region have resulted from the water diversions and flood control measures along the Colorado River. These measures have altered the region's hydrology by redistributing the region's water supp
Anza-Borrego Desert State Park
Anza-Borrego Desert State Park is a California state park located within the Colorado Desert of southern California, United States. The park takes its name from 18th century Spanish explorer Juan Bautista de Anza and borrego, the Spanish word for sheep. With 600,000 acres that includes one-fifth of San Diego County, it is the largest state park in California; the park occupies eastern San Diego County and reaches into Imperial and Riverside counties, enveloping two communities: Borrego Springs, home to the park's headquarters, Shelter Valley. The park is an anchor in the Mojave and Colorado Deserts Biosphere Reserve, adjacent to the Santa Rosa and San Jacinto Mountains National Monument; the great bowl of the surrounding desert is surrounded by mountains, with the Vallecito Mountains to the south and the highest Santa Rosa Mountains to the north which are in the wilderness area, without paved roads and with the only year-round creeks. The park has 500 mi of dirt roads, 12 designated wilderness areas, 110 mi of hiking trails.
ABDSP is around a two-hour drive northeast from San Diego, southeast from Riverside or Irvine, south from Palm Springs. Access on the east-Coachella Valley side is via County Route S22 and State Route 78. Access on the west-Pacific Ocean side is via California County Routes S79. S67 provides access through the high and forested Laguna Mountains, such as in Cuyamaca Rancho State Park; these highways climb from the coast to 2,400 ft above sea level descend 2,000 ft down into the Borrego Valley in the center of the park. Park information and maps are available in the Visitor Center; the park has Wi-Fi access. The habitats are within the Colorado Desert ecosystem of the Sonoran Desert ecoregion; the higher extreme northern and eastern sections in the Peninsular Ranges are in the California montane chaparral and woodlands ecoregion. The park contains bajadas and desert washes; the bajadas are predominantly creosote bush-bur sage with creosote bush and the palo verde-cactus shrub ecosystems with the palo verde tree and ocotillo.
In the washes, Colorado/Sonoran microphylla woodlands can be found. These woodlands include such plants as smoke tree, velvet mesquite, catclaw; the park has natural oases, with the state's only native palm, the California Fan Palm. Seasonal wildflower displays can be seen in many plant community association throughout the park; the high-country to the north and east has closed-cone pine forests and oak woodlands. The oases are prolific with many types of fauna for bird-watching. Throughout the park, visitors may see bighorn sheep, mountain lions, kit foxes, mule deer, greater roadrunners, golden eagles, black-tailed jackrabbits, ground squirrels, kangaroo rats and prairie falcons. In the reptile class, desert iguanas and the red diamond rattlesnakes can be seen; some areas are habitats for the Peninsular bighorn sheep called desert bighorn sheep. Few park visitors see them, the sheep avoid human contact. Observers count this endangered species to study the population, monitor its current decline from human encroachment.
The expanses of ABDSP's eroded badlands provide a different view into the region's long-vanished tropical past. The inland of southeastern California was not always a desert. Paleontology, the study of the fossilized remains of ancient life, is the key to understanding this prehistoric world. ABDSP has an exceptional fossil record which includes preserved plants, a variety of invertebrate shells, animal tracks, an array of bones and teeth. Most fossils found in ABDSP date from six million to under a half million years in age, or about 60 million years after the last dinosaur age ended. ABDSP lies in a unique geologic setting along the western margin of the Salton Trough; this major topographic depression with the Salton Sink having elevations of 200 ft below sea level, forms the northernmost end of an active rift valley and a geological continental plate boundary. The trough extends north from the Gulf of California to San Gorgonio Pass, from the eastern rim of the Peninsular Ranges eastward to the San Andreas Fault zone along the far side of the Coachella Valley.
Over the past seven million years, a complete geologic record of over 20,000 ft of fossil-bearing sediment has been deposited within the park along the rift valley's western margin. Paleontological remains are widespread and diverse, are found scattered over hundreds of square miles of eroded badlands terrain extending south from the Santa Rosa Mountains into northern Baja California in Mexico. Both marine and terrestrial environments are represented by this rich fossil record. Six million years ago, the ancestral Gulf of California filled the Salton Trough, extending northward past what would become the city of Palm Springs; these tropical waters supported a profusion of both small marine organisms. Through time, the sea gave way as an immense volume of sediment eroded during the formation of the Grand Canyon spilled into the Salton Trough. Little by little, the ancestral Colorado River built a massive river delta across the sea way. Fossil hardwoods from the deltaic sands and associated coastal plain deposits suggest the region received three times as much rainfall as now.
The Anza-Borrego region changed from a predominately marine environment into a system of interrelated terrestrial habitats. North of the Colorado River Delta and intermittently fed by the river, a
Death Valley National Park
Death Valley National Park is an American national park that straddles the California—Nevada border, east of the Sierra Nevada. The park boundaries include Death Valley, the northern section of Panamint Valley, the southern section of Eureka Valley, most of Saline Valley; the park occupies an interface zone between the arid Great Basin and Mojave deserts, protecting the northwest corner of the Mojave Desert and its diverse environment of salt-flats, sand dunes, valleys and mountains. Death Valley is the largest national park in the lower 48 states, the hottest and lowest of all the national parks in the United States; the second-lowest point in the Western Hemisphere is in Badwater Basin, 282 feet below sea level. 91% of the park is a designated wilderness area. The park is home to many species of plants and animals that have adapted to this harsh desert environment; some examples include creosote bush, bighorn sheep and the Death Valley pupfish, a survivor from much wetter times. UNESCO included Death Valley as the principal feature of its Mojave and Colorado Deserts Biosphere Reserve in 1984.
A series of Native American groups inhabited the area from as early as 7000 BC, most the Timbisha around 1000 AD who migrated between winter camps in the valleys and summer grounds in the mountains. A group of European-Americans, trapped in the valley in 1849 while looking for a shortcut to the gold fields of California, gave the valley its name though only one of their group died there. Several short-lived boom towns sprang up during the late 19th and early 20th centuries to mine gold and silver; the only long-term profitable ore to be mined was borax, transported out of the valley with twenty-mule teams. The valley became the subject of books, radio programs, television series, movies. Tourism expanded in the 1920s when resorts were built around Furnace Creek. Death Valley National Monument was declared in 1933 and the park was expanded and became a national park in 1994; the natural environment of the area has been shaped by its geology. The valley is a graben with the oldest rocks being extensively metamorphosed and at least 1.7 billion years old.
Ancient, shallow seas deposited marine sediments until rifting opened the Pacific Ocean. Additional sedimentation occurred; the subduction created a line of volcanoes. The crust started to pull apart, creating the current Basin and Range landform. Valleys filled with sediment and, during the wet times of glacial periods, with lakes, such as Lake Manly. In 2013, Death Valley National Park was designated as a dark sky park by the International Dark-Sky Association. There are two major valleys in Death Valley and Panamint Valley. Both of these valleys were formed within the last few million years and both are bounded by north–south-trending mountain ranges; these and adjacent valleys follow the general trend of Basin and Range topography with one modification: there are parallel strike-slip faults that perpendicularly bound the central extent of Death Valley. The result of this shearing action is additional extension in the central part of Death Valley which causes a slight widening and more subsidence there.
Uplift of surrounding mountain ranges and subsidence of the valley floor are both occurring. The uplift on the Black Mountains is so fast that the alluvial fans there are small and steep compared to the huge alluvial fans coming off the Panamint Range. Fast uplift of a mountain range in an arid environment does not allow its canyons enough time to cut a classic V-shape all the way down to the stream bed. Instead, a V-shape ends at a slot canyon halfway down, forming a'wine glass canyon.' Sediment is deposited on a steep alluvial fan. At 282 feet below sea level at its lowest point, Badwater Basin on Death Valley's floor is the second-lowest depression in the Western Hemisphere, while Mount Whitney, only 85 miles to the west, rises to 14,505 feet; this topographic relief is the greatest elevation gradient in the contiguous United States and is the terminus point of the Great Basin's southwestern drainage. Although the extreme lack of water in the Great Basin makes this distinction of little current practical use, it does mean that in wetter times the lake that once filled Death Valley was the last stop for water flowing in the region, meaning the water there was saturated in dissolved materials.
Thus the salt pans in Death Valley are among the largest in the world and are rich in minerals, such as borax and various salts and hydrates. The largest salt pan in the park extends 40 miles from the Ashford Mill Site to the Salt Creek Hills, covering some 200 square miles of the valley floor; the best known playa in the park is the Racetrack, known for its moving rocks. Death Valley is the hottest and driest place in North America due to its lack of surface water and low relief, it is so the hottest spot in the United States that many tabulations of the highest daily temperatures in the country omit Death Valley as a matter of course. On the afternoon of July 10, 1913, the United States Weather Bureau recorded a high temperature of 134 °F at Greenland Ranch in Death Valley; this temperature stands as the highest ambient air temperature recorded at the surface of the Earth. Daily summer temperatures of 120 °F or greater are common, as well as below freezing nightly temperatur
Santa Rosa Mountains (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 Santa Rosa Mountains extend for 30 miles along the western side of the Coachella Valley within Riverside, San Diego, Imperial Counties in Southern California; the range connects to the San Jacinto Mountains on its northern end, where the Pines to Palms Highway—California State Route 74, crosses them. The highest peak in the range is Toro Peak, located 22 miles south of Palm Springs, just south of Route 74, on the northeast side of Anza-Borrego's Upper Coyote Canyon; the Santa Rosa Mountains are a Great Basin Divide landform for the Salton Sink Watershed on the east. The oldest accounts of the southeastern reaches of the Santa Rosa Mountains survive from the 1774 Spanish expedition led by explorer Juan Bautista de Anza into colonial Las Californias through the Coachella Valley from the populated Viceroyalty of New Spain region.
19th century maps of the region show the Santa Rosas as a southern extension of the higher northern San Jacinto Mountains. The name "Santa Rosa Mountains" first came into use by the USGS in 1901; the Santa Rosa range lies within the Colorado Desert and California montane chaparral and woodlands ecoregions of flora and fauna. The California desert chaparral flora and fauna community is found here on the eastern rainshadow side. In the eastern Santa Rosa Mountains, in canyons with natural oases, the native California Fan Palm is found, they are the home of a population of endangered Peninsular Bighorn Sheep, endemic to the Peninsular Ranges and distinct from the Desert Bighorn Sheep. Most of the northern portion of the range, in Riverside County, is within the Santa Rosa and San Jacinto Mountains National Monument, it was created in 2000 and is administered jointly by the US Bureau of Land Management and U. S. Forest Service—San Bernardino National Forest; the southern portion of the range, with Toro Peak, is west of the Salton Sea and within the northeastern Borrego Badlands area of the expansive Anza-Borrego Desert State Park.
Both provide interpretive visitor centers and many trails for experiencing the Santa Rosa Mountains at all elevations. In 1990 the California Legislature created the Coachella Valley Mountains Conservancy to protect this and other mountain ranges surrounding the Coachella Valley. Juan Bautista de Anza National Historic Trail Mojave and Colorado Deserts Biosphere Reserve U. S. Forest Service: official USFS Santa Rosa and San Jacinto Mountains National Monument website Bureau of Land Management: official BLM Santa Rosa and San Jacinto Mountains National Monument website "Santa Rosa Mountains". Geographic Names Information System. United States Geological Survey
Death Valley is a desert valley located in Eastern California, in the northern Mojave Desert bordering the Great Basin Desert. It is one of the hottest places in the world along with deserts in the Middle East. Death Valley's Badwater Basin is the point of the lowest elevation in North America, at 282 feet below sea level; this point is 84.6 miles east-southeast of Mount Whitney, the highest point in the contiguous United States, with an elevation of 14,505 feet. On the afternoon of July 10, 1913, the United States Weather Bureau recorded a high temperature of 134 °F at Furnace Creek in Death Valley; this temperature stands as the highest ambient air temperature recorded at the surface of the Earth. Located near the border of California and Nevada, in the Great Basin, east of the Sierra Nevada mountains, Death Valley constitutes much of Death Valley National Park and is the principal feature of the Mojave and Colorado Deserts Biosphere Reserve, it is located in Inyo County, California. It runs from north to south between the Amargosa Range on the east and the Panamint Range on the west.
It has an area of about 3,000 sq mi. The highest point in Death Valley itself is Telescope Peak in the Panamint Range, which has an elevation of 11,043 feet. Death Valley is an excellent example of a graben, or a downdropped block of land between two mountain ranges, it lies at the southern end of a geological trough known as Walker Lane. The valley is bisected by a right lateral strike slip fault system, represented by the Death Valley Fault and the Furnace Creek Fault; the eastern end of the left lateral Garlock Fault intersects the Death Valley Fault. Furnace Creek and the Amargosa River flow through the valley but disappear into the sands of the valley floor. Death Valley contains salt pans. According to current geological consensus, at various times during the middle of the Pleistocene era, which ended 10,000–12,000 years ago, an inland lake referred to as Lake Manly formed in Death Valley. Lake Manly was nearly 100 miles long and 600 feet deep, the end-basin in a chain of lakes that began with Mono Lake in the north and continued through multiple basins down the Owens River Valley through Searles and China Lakes and the Panamint Valley to the immediate west.
As the area turned to desert, the water evaporated, leaving the abundance of evaporitic salts such as common sodium salts and borax, which were exploited during the modern history of the region 1883 to 1907. Death Valley has a subtropical, hot desert climate, with long hot summers and short, mild winters, as well as little rainfall; as a general rule, lower altitudes tend to have higher temperatures. When the sun heats the ground, that heat is radiated upward, but the dense below-sea-level air absorbs some of this radiation and radiates some of it back towards the ground. In addition, the high valley walls trap rising hot air and recycle it back down to the valley floor, where it is heated by compression; this process is important in Death Valley, as it provides its specific climate and geography. The valley is surrounded by mountains, while its surface is flat and devoid of plants, so much of the sun's heat can reach the ground, absorbed by soil and rock; when air at ground level is heated, it begins to rise, moving up past steep, high mountain ranges, which cools sinking back down towards the valley more compressed.
This air is reheated by the sun to a higher temperature, moving up the mountain again, whereby the air moves up and down in a circular motion in cycles, similar to how a convection oven works. This heated air increases ground temperature markedly, forming the hot wind currents that are trapped by atmospheric pressure and mountains and thus stay within the valley; such hot wind currents contribute to perpetual drought-like conditions in Death Valley and prevent much cloud formation from passing through the confines of the valley, where precipitation is in the form of a virga. Death Valley holds temperature records because it has an unusually high number of factors that lead to high atmospheric temperatures; the depth and shape of Death Valley influence its summer temperatures. The valley is a long, narrow basin 282 feet below sea level, yet is walled by high, steep mountain ranges; the clear, dry air and sparse plant cover allow sunlight to heat the desert surface. Summer nights provide little relief.
Moving masses of super-heated air blow through the valley creating high temperatures. The hottest air temperature recorded in Death Valley was 134 °F on July 10, 1913, at Greenland Ranch, the highest atmospheric temperature recorded on earth. A report of a temperature of 58 °C recorded in Libya in 1922 was determined to be inaccurate. During the heat wave that peaked with that record, five consecutive days reached 129 above; some meteorologists dispute the accuracy of the 1913 temperature measurement. The highest surface temperature recorded in Death Valley was 201.0 °F on July 15, 1972, at Furnace Creek, the highest ground surface temperature recorded on earth, as well as the only recorded surface temperature of above 200 °F. The greatest number of consecutive days with a maximum temperature of 100 °F or above was 154 days in the summer of 2001; the summer of 1996 had 40 days over 120 °F, 105 days over 110 °F. The summer of 1917 had 52 days where the temperature
Riverside County, California
Riverside County is one of fifty-eight counties in the U. S. state of California. As of the 2010 census, the population was 2,189,641, making it the 4th-most populous county in California and the 11th-most populous in the United States; the name was derived from the city of Riverside, the county seat. Riverside County is included in the Riverside-San Bernardino-Ontario, CA Metropolitan Statistical Area known as the Inland Empire; the county is included in the Los Angeles-Long Beach, CA Combined Statistical Area. There is a high concentration of sprawling tract housing communities around Riverside and along the Interstate 10, 15, 215 freeways. Rectangular, Riverside County covers 7,208 square miles in Southern California, spanning from the Greater Los Angeles area to the Arizona border. Geographically, the county is desert in the central and eastern portions, but has a Mediterranean climate in the western portion. Most of Joshua Tree National Park is located in the county; the resort cities of Palm Springs, Palm Desert, Indian Wells, La Quinta, Rancho Mirage, Desert Hot Springs are all located in the Coachella Valley region of central Riverside County.
Large numbers of Los Angeles area workers have moved to the county in recent years to take advantage of affordable housing. Along with neighboring San Bernardino County, it was one of the fastest growing regions in the state prior to the recent changes in the regional economy. In addition, but significant, numbers of people have been moving into Southwest Riverside County from the San Diego-Tijuana metropolitan area; the cities of Temecula and Murrieta accounted for 20% of the increase in population of the county between 2000 and 2007. Riverside County was named for the Santa Ana River in 1870; the indigenous peoples of what is now Riverside County are Cupeño and Cahuilla Indians. The Luiseño lived in the Aguanga and Temecula Basins, Elsinore Trough and eastern Santa Ana Mountains and southward into San Diego County; the Cahuilla lived to the east and north of the Luiseño in the inland valleys, in the Santa Rosa and San Jacinto Mountains and the desert of the Salton Sink. The first European settlement in the county was a Mission San Luis Rey de Francia estancia or farm, at the Luiseño village of Temecula.
Grain and grapes were grown here. In 1819, the Mission granted land to Leandro Serrano, mayordomo of San Antonio de Pala Asistencia for the Mission of San Luis Rey for Rancho Temescal. Following Mexican independence and the 1833 confiscation of Mission lands, more ranchos were granted. Rancho Jurupa in 1838, El Rincon in 1839, Rancho San Jacinto Viejo in 1842, Rancho San Jacinto y San Gorgonio in 1843, Ranchos La Laguna, Temecula in 1844, Ranchos Little Temecula, Potreros de San Juan Capistrano in 1845, Ranchos San Jacinto Sobrante, La Sierra, La Sierra, Santa Rosa and San Jacinto Nuevo y Potrero in 1846. New Mexican colonists founded the town of La Placita on the east side of the Santa Ana River at the northern extremity of what is now the city of Riverside in 1843; when the initial 27 California counties were established in 1850, the area today known as Riverside County was divided between Los Angeles County and San Diego County. In 1853, the eastern part of Los Angeles County was used to create San Bernardino County.
Between 1891 and 1893, several proposals and legislative attempts were put forth to form new counties in Southern California. These proposals included one for one for a San Jacinto County. None of the proposals were adopted until a measure to create Riverside County was signed by Governor Henry H. Markham on March 11, 1893; the new county was created from parts of San Diego County. On May 2, 1893, seventy percent of voters approved the formation of Riverside County. Voters chose the city of Riverside as the county seat by a large margin. Riverside County was formed on May 9, 1893, when the Board of Commissioners filed the final canvass of the votes. Riverside County is the birthplace of lane markings, thanks to Dr. June McCarroll in 1915 when she suggested her idea to the state government; the county is the location of the March Air Reserve Base, one of the oldest airfields continuously operated by the United States military. Established as the Alessandro Flying Training Field in February 1918, it was one of thirty-two U.
S. Army Air Service training camps established after the United States entry into World War I in April 1917; the airfield was renamed March Field the following month for 2d Lieutenant Peyton C. March, Jr. the deceased son of the then-Army Chief of Staff, General Peyton C. March, killed in an air crash in Texas just fifteen days after being commissioned. March Field remained an active Army Air Service U. S. Army Air Corps installation throughout the interwar period becoming a major installation of the U. S. Army Air Forces during World War II. Renamed March Air Force Base in 1947 following the establishment of the U. S. Air Force, it was a major Strategic Air Command installation throughout the Cold War. In 1996, it was transferred to the Air Force Reserve Command and gained its current name as a major base for the Air Force Reserve and the California Air National Guard. Riverside county was a major focal point of the Civil Rights Movements in the US the African-American sections of Riverside and Mexican-American communities of the Coachella Valley visited by Cesar Chavez of the farm labor union struggle.
Riverside county has been a focus of modern Native American Gaming enterprises. In the early 1980s, the county government attempted to shut down small bingo halls operated by the Morongo Band of Cahuilla Mission In
Joshua Tree National Park
Joshua Tree National Park is an American national park in southeastern California, east of Los Angeles, near San Bernardino and Palm Springs. The park is named for the Joshua trees native to the Mojave Desert. 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 790,636 acres —an area larger than the state of Rhode Island—the park includes 429,690 acres of designated wilderness. Straddling the border between San Bernardino County and Riverside County, the park includes parts of two deserts, each an ecosystem whose characteristics are determined by elevation: the higher Mojave Desert and the lower Colorado Desert; the Little San Bernardino Mountains traverse the southwest edge of the park. The earliest known residents of the land in and around what became Joshua Tree National Park were the people of the Pinto Culture, who lived and hunted here between 8000 and 4000 BCE.
Their stone tools and spear points, discovered in the Pinto Basin in the 1930s, suggest that they hunted game and gathered seasonal plants, but little else is known about them. Residents included the Serrano, the Cahuilla, the Chemehuevi peoples. All three lived at times in small villages in or near water the Oasis of Mara in what non-aboriginals called Twentynine Palms, they were hunter-gatherers who subsisted on plant foods supplemented by small game and reptiles while using other plants for making medicines and arrows, other articles of daily life. A fourth group, the Mojaves, used the local resources as they traveled along trails between the Colorado River and the Pacific coast. In the 21st century, small numbers of all four peoples live in the region near the park. In 1772, a group of Spaniards led by Pedro Fages, made the first European sightings of Joshua trees while pursuing native converts to Christianity who had run away from a mission in San Diego. By 1823, the year Mexico achieved independence from Spain, a Mexican expedition from Los Angeles, in what was Alta California, is thought to have explored as far east as the Eagle Mountains in what became the park.
Three years Jedediah Smith led a group of American fur trappers and explorers along the nearby Mojave Trail, others soon followed. Two decades after that, the United States defeated Mexico in the Mexican–American War and took over about half of Mexico's original territory, including California and the future parkland. In 1870, white settlers began grazing cattle on the tall grasses. In 1888, a gang of cattle rustlers moved into the region near the Oasis of Mara. Led by brothers James. B. and William S. McHaney, they hid stolen cattle in a box canyon at Cow Camp. Throughout the region, ranchers dug wells and built rainwater catchments called "tanks", such as White Tank and Barker Dam. In 1900, C. O. Barker, a miner and cattleman, built the original Barker Dam improved by William "Bill" Keys, a rancher. Grazing continued in the park through 1945. Barker Dam was added to the National Register of Historic Places in 1975. Between the 1860s and the 1940s, miners worked about 300 pit mines small, in what became the park.
The most successful, the Lost Horse Mine, produced gold and silver worth about $5 million in today's currency. Johnny Lang and others, the original owners of the Lost Horse Mine, installed a two-stamp mill to process ore at the site, the next owner, J. D. Ryan, replaced it with a 10-stamp steam-powered mill. Ryan pumped water from his ranch to the mill and cut timber from the nearby hills to heat water to make steam. Most of the structures associated with the mine fell apart, for safety reasons the National Park Service plugged the mine, which had collapsed; the Desert Queen Mine on Keys' Desert Queen Ranch was another productive gold mine. In the early 1930s, Keys bought a gasoline-powered two-stamp mill, the Wall Street Mill, moved it to his ranch to process ore; the ranch and mill were added to the NRHP in 1975 and the mine in 1976. Some of the mines in the park yielded copper and iron. On August 10, 1936, after Minerva Hoyt and others persuaded the state and federal governments to protect the area, president Franklin D. Roosevelt used the power of the 1906 Antiquities Act to establish Joshua Tree National Monument, protecting about 825,000 acres.
In 1950, the size of the park was reduced by about 290,000 acres to open the land to more mining. The monument was redesignated as a national park on October 31, 1994, by the Desert Protection Act, which added 234,000 acres. In 2019, the park expanded by 4,518 acres under a bill included in the John D. Dingell, Jr. Conservation and Recreation Act; the higher and cooler Mojave Desert is the special habitat of Yucca brevifolia, the Joshua tree for which the park is named. It occurs in patterns from dense forests to distantly spaced specimens. In addition to Joshua tree forests, the western part of the park includes some of the most interesting geologic displays found in California's deserts; the dominant geologic features of this landscape are hills of bare rock broken up into loose boulders. These hills are popular among rock scrambling enthusiasts; the flatland between these hills is sparsely forested with Joshua trees. Together with the boulder piles and Skull Rock, the trees make the landscape otherworldly.
Temperatures are most comfortable