CaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
's
Colorado Desert is a part of the larger
Sonoran DesertThe Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the northwest Mexican states of Sonora, Baja California, and Baja California Sur. It is one of the largest and hottest...
, which extends across southwest North America. The Colorado Desert region encompasses approximately 7 million acres (2,832,802 ha), reaching from the
MexicanThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
border in the south to the higher-elevation
Mojave DesertThe Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
in the north and from the
Colorado RiverThe Colorado River , is a river in 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 watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
in the east to the
Laguna MountainsThe Laguna Mountains are a section of the Peninsular Ranges in eastern San Diego County, California. The mountains run in a northwest/southeast alignment for approximately ....
of the
Peninsular RangesThe Peninsular Ranges are a group of mountain ranges, in the Pacific Coast Ranges, which stretch from southern California in the United States to the southern tip of Mexico's Baja California peninsula; they are part of the North American Coast Ranges that run along the Pacific coast from Alaska...
in the west. The area includes the heavily
irrigatedIrrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
CoachellaCoachella Valley is a large valley landform in Southern California. The valley extends for approximately 45 miles in Riverside County southeast from the San Bernardino Mountains to the saltwater Salton Sea, the largest lake in California...
and
Imperial ValleyThe Imperial Valley is an agricultural area of Southern California's Imperial County. It is located in southeastern Southern California, centered around the city of El Centro. Locally, the terms "Imperial Valley" and "Imperial County" are used synonymously. The Valley is bordered between the...
s. The Colorado Desert is home to many unique flora and fauna, many of which can be found nowhere else on the planet.
Geography and geology
The Colorado Desert region encompasses approximately 7 million acres (28,328 km²), reaching from the Mexican border in the south to the higher-elevation Mojave Desert in the north and from the
Colorado RiverThe Colorado River , is a river in 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 watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
in the east to the
Laguna MountainsThe Laguna Mountains are a section of the Peninsular Ranges in eastern San Diego County, California. The mountains run in a northwest/southeast alignment for approximately ....
of the
Peninsular RangesThe Peninsular Ranges are a group of mountain ranges, in the Pacific Coast Ranges, which stretch from southern California in the United States to the southern tip of Mexico's Baja California peninsula; they are part of the North American Coast Ranges that run along the Pacific coast from Alaska...
in the west. The desert encompasses
Imperial CountyImperial County is a county located in the Imperial Valley, in the far southeast of the U.S. state of California, bordering both Arizona and Mexico. It is part of the El Centro Metropolitan Area, which encompasses all of Imperial County. The population as of 2000 was 142,361. The county seat is the...
and includes parts of
San Diego CountySan Diego County is a large county located in the southwestern corner of the US state of California. Hence, San Diego County is also located in the southwestern corner of the 48 contiguous United States. Its county seat and largest city is San Diego. Its population was about 2,813,835 in the 2000...
,
Riverside CountyRiverside County is a county in the U.S. state of California. One of 58 California counties, it covers in the southern part of the state, and stretches from Orange County to the Colorado River, which forms the state border with Arizona. The county derives its name from the city of Riverside,...
, and a very small part of
San Bernardino CountySan Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
.
The majority of the Colorado Desert lies at a relatively low elevation, below 1000 feet (304.8 m), with the lowest point of the desert floor at 275 feet (83.8 m) below sea level at the
Salton SeaThe Salton Sea is a shallow, saline, endorheic rift lake located directly on the San Andreas Fault, predominantly in California's Imperial Valley. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Imperial and Riverside counties in Southern California. Like Death...
. Although the highest peaks of the Peninsular Range reach elevations of nearly 10000 feet (3,048 m), most of the region's mountains do not exceed 3000 feet (914.4 m).
In this region, the
geologyGeology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
is dominated by the transition of the tectonic plate boundary from
riftIn geology, a rift or chasm is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics....
to fault. The southernmost strands of the
San Andreas FaultThe San Andreas Fault is a continental strike-slip fault that runs a length of roughly through California in the United States. The fault's motion is right-lateral strike-slip...
connect to the northern-most extensions of the
East Pacific RiseThe East Pacific Rise is a mid-oceanic ridge, a divergent tectonic plate boundary located along the floor of the Pacific Ocean. It separates the Pacific Plate to the west from the North American Plate, the Rivera Plate, the Cocos Plate, the Nazca Plate, and the Antarctic Plate...
. Consequently, the region is subject to
earthquakeAn earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
s, and the crust is being stretched, resulting in a sinking of the terrain over time.
Climate
The Colorado Desert's climate distinguishes it from other deserts. The region experiences greater summer daytime temperatures than higher-elevation deserts and almost never experiences frost. In addition, the Colorado Desert experiences two rainy seasons per year (in the winter and late summer), especially toward the southern portion of the region; the more northerly Mojave Desert has only winter rains.
The west coast Peninsular Ranges, or other west ranges, of Southern California–northern
Baja CaliforniaBaja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, 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 CaliforniaThe Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
to the south, and are often active in the summer
monsoonMonsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...
s. These include remnants of Pacific hurricanes, storms from the southern tropical
jetstreamJetStream and Mobile JetStream are two former brand names used by Telecom New Zealand to market its retail and resale ADSL-based fixed line and CDMA2000-based 3G wireless Internet access offerings respectively...
, and the northern
ITCZThe Intertropical Convergence Zone , known by sailors as The Doldrums, is the area encircling the earth near the equator where winds originating in the northern and southern hemispheres come together....
.
Flora and fauna
The region's terrestrial habitats include
creosote bushLarrea tridentata is known as Creosote bush as a plant, chaparral as a medicinal herb, and as "gobernadora" in Mexico, Spanish for "governess," due to its ability for inhibiting the growth of nearby plants to have more water. In Sonora, it is more commonly called "hediondilla." It is a flowering...
scrub; mixed scrub, including
yuccaYucca is a genus of perennial shrubs and trees in the family Asparagaceae, subfamily Agavoideae. Its 40-50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flowers. They are native to the hot and dry parts of North...
and cholla cactus; desert saltbush; sandy soil grasslands; and desert dunes. Higher elevations are dominated by
pinyon pineThe pinyon pine group grows in the southwestern United States and in Mexico. The trees yield edible pinyon nuts, which were a staple of the Native Americans, and are still widely eaten...
and
California juniperJuniperus californica is a species of juniper native to southwestern North America; as the name implies, it is mainly found in California, although its range also extends through most of Baja California, a short distance into the Great Basin in southern Nevada, and western Arizona...
, with areas of
manzanitaManzanita is a common name for many species of the genus Arctostaphylos. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from southern British Columbia, Washington to California, Arizona and New Mexico in the United States, and...
and
Coulter pineThe Coulter Pine or Big-cone Pine is a native of the coastal mountains of southern California and northern Baja California . Isolated groves are found as far north as the San Francisco Bay Area in Mt. Diablo State Park and Black Diamond Mines Regional Preserve...
. In addition to hardy perennials, more than half of the desert's plant species are herbaceous annuals, and 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, ironwood, and
palo verde-Botany:*Palo Verde trees, several species of the genus Parkinsonia **Mexican Palo Verde **Blue Palo Verde **Yellow or Foothill Palo Verde gay-Places:...
trees. The unique
Joshua TreeYucca brevifolia is a plant species belonging to the genus Yucca. It is tree-like in habit, which is reflected in its common names: Joshua tree, Yucca palm, Tree yucca, and Palm tree yucca....
can be found in
Joshua Tree National ParkJoshua Tree National Park is located in southeastern California. Declared a U.S. National Park in 1994 when the U.S. Congress passed the California Desert Protection Act , it had previously been a U.S. National Monument since 1936. It is named for the Joshua tree forests native to the park...
, as well as small regions of central or northwestern Arizona.
Common desert wildlife include
mule deerThe mule deer is a deer indigenous to western North America. The Mule Deer gets its name from its large mule-like ears. There are believed to be several subspecies, including the black-tailed deer...
,
bobcatThe bobcat is a North American mammal of the cat family Felidae, appearing during the Irvingtonian stage of around 1.8 million years ago . With twelve recognized subspecies, it ranges from southern Canada to northern Mexico, including most of the continental United States...
, desert
kangaroo ratKangaroo rats, genus Dipodomys, are small rodents native to North America. The common name derives from their bipedal form: as they hop in a manner similar to the much larger kangaroo, although they are not related...
, cactus
mouseA mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
,
black-tailed jackrabbitThe black-tailed jackrabbit , also known as the american desert hare, is a common hare of the western United States and Mexico, where it is found at elevations from sea level to up to...
, Gambel's
quailQuail is a collective name for several genera of mid-sized birds generally considered in the order Galliformes. Old World quail are found in the family Phasianidae, while New World quail are found in the family Odontophoridae...
, and red-diamond
rattlesnakeRattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
. Among sensitive species are flat-tailed horned
lizardLizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
, Coachella Valley fringe-toed lizard,
desert tortoiseThe desert tortoise is a species of tortoise native to the Mojave desert and Sonoran desert of the southwestern United States and northwestern Mexico. They can be located in western Arizona, southeastern California, southern Nevada, and southwestern Utah. The species name agassizii is in honor of...
,
prairie falconThe Prairie Falcon is a medium-sized falcon of western North America.It is about the size of a Peregrine Falcon or a crow, with an average length of 40 cm , wingspan of 1 metre , and weight of 720 g...
, Andrews' dune scarab beetle, Peninsular
bighorn sheepThe bighorn sheep is a species of sheep in North America named for its large horns. These horns can weigh up to , while the sheep themselves weigh up to . Recent genetic testing indicates that there are three distinct subspecies of Ovis canadensis, one of which is endangered: Ovis canadensis sierrae...
, and California
leaf-nosed batThe New World leaf-nosed bats are found throughout Central and South America, from Mexico to northern Argentina. They are ecologically the most varied and diverse family within the order Chiroptera...
.
In the Colorado Desert's arid environment, aquatic and
wetlandA wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
habitats are limited in extent but are critically important to wildlife. Runoff from seasonal rains and groundwater springs forms desert
arroyosAn arroyo , a Spanish word translated as brook, and also called a wash is usually a dry creek or stream bed—gulch that temporarily or seasonally fills and flows after sufficient rain. Wadi is a similar term in Africa. In Spain, a rambla has a similar meaning to arroyo.-Types and processes:Arroyos...
, desert fan palm
oasesIn geography, an oasis or cienega is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source...
, freshwater marshes, brine lakes, desert washes, ephemeral and perennial streams, and riparian vegetation communities dominated by cottonwood,
willowWillows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...
, and non-native tamarisk. Two of the region's most significant aquatic systems are the
Salton SeaThe Salton Sea is a shallow, saline, endorheic rift lake located directly on the San Andreas Fault, predominantly in California's Imperial Valley. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Imperial and Riverside counties in Southern California. Like Death...
and the
Colorado RiverThe Colorado River , is a river in 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 watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
. While most desert wildlife depend on aquatic habitats as water sources, a number of species, such as arroyo
toadA toad is any of a number of species of amphibians in the order Anura characterized by dry, leathery skin , short legs, and snoat-like parotoid glands...
, desert pupfish, Yuma clapper rail, and southwestern willow
flycatcherThere are various families of bird termed flycatchers:* The Old World flycatchers, Muscicapidae* The Tyrant flycatchers, Tyrannidae* The Monarch flycatchers, Dicruridae* The Silky-flycatchers, Ptilogonatidae* The Fairy flycatchers, Stenostiridae...
, 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 ecological communities found only in the Colorado Desert. They occur only where permanent water sources are available, such as at springs or along fault lines, where
groundwaterGroundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
is forced to the surface by the movement of hard impermeable rock, and can be found in the San Jacinto, Santa Rosa, and Little San Bernardino mountains, in the canyons of
Anza-Borrego Desert State ParkAnza-Borrego Desert State Park is a state park located within the Colorado Desert of Southern California. The park takes its name from 18th century, Spanish explorer Juan Bautista de Anza and borrego, the Spanish word for bighorn sheep...
, and along the
San Andreas FaultThe San Andreas Fault is a continental strike-slip fault that runs a length of roughly through California in the United States. The fault's motion is right-lateral strike-slip...
in the
Coachella ValleyCoachella Valley is a large valley landform in Southern California. The valley extends for approximately 45 miles in Riverside County southeast from the San Bernardino Mountains to the saltwater Salton Sea, the largest lake in California...
. The only palm native to California,
Washingtonia filiferaWashingtonia filifera , with the common names California Fan Palm , Desert Fan Palm, Cotton palm, and Arizona Fan Palm. It is a palm native to southwestern North America between an elevation range of , at seeps, desert bajadas, and springs where underground water is continuously available...
(desert fan palm), grow at the oases.
Endemic flora
Some sub-regions of the Colorado Desert contain endemic flora. Along the
Lower Colorado River ValleyThe Lower Colorado River Valley is the river region of the lower Colorado River of the southwestern United States in North America that rises in the Rocky Mountains and has its outlet at the Colorado River Delta in the northern Sea of Cortez in northwestern Mexico, between the states of Baja...
, in-flow side canyons, flatlands, or low to higher level elevations, at least three endemic flora exist:
Hesperocallis undulata (desert lily),
Nolina bigeloviiNolina bigelovii, Bigelow's nolina or beargrass, is a flowering plant native to the Southwestern United States, California, and Northwest Mexico...
(Bigelow's nolina), and
Peucephyllum schottii (desert fir).
National and State Parks
- Joshua Tree National Park
Joshua Tree National Park is located in southeastern California. Declared a U.S. National Park in 1994 when the U.S. Congress passed the California Desert Protection Act , it had previously been a U.S. National Monument since 1936. It is named for the Joshua tree forests native to the park...
- 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...
- 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...
- Indio Hills Palms
Indio Hills Palms State Reserve and the Coachella Valley Preserve, located in the Indio Hills, contain the 1,000 Palms Oasis, and are a protected area in the Coachella Valley, located east of Palm Springs near Palm Desert, California...
- Anza-Borrego Desert State Park
Anza-Borrego Desert State Park is a state park located within the Colorado Desert of Southern California. The park takes its name from 18th century, Spanish explorer Juan Bautista de Anza and borrego, the Spanish word for bighorn sheep...
- Ocotillo Wells State Vehicular Recreation Area
- Picacho State Recreation Area
Picacho State Recreation Area is located on the lower Colorado river at the site of Picacho, a defunct gold mining town.-Proposed for closure:...
- Heber Dunes State Vehicular Recreation Area
- Salton Sea State Recreation Area
Located on the northeastern side of the Salton Sea, the Salton Sea State Recreation Area offers hunting, fishing, swimming, and camping to visitors.-Recreation:The Salton Sea State Recreation Area is run by the California Department of Parks and Recreation....
Environmental issues
Although the Colorado Desert remains one of the least-populous regions in California, human activities have had substantial impacts on the region's habitats and wildlife. Many unique communities, particularly aquatic and dune systems, are limited in distribution and separated by vast expanses of inhospitable, arid desert terrain. Even 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 RiverThe Colorado River , is a river in 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 watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
. These measures have dramatically altered the region's
hydrologyHydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
by redistributing the region's water supply to large expanses of irrigated
agricultureAgriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
and metropolitan coastal areas such as
Los AngelesLos Angeles , with a population at the 2010 United States Census of 3,792,621, is the most populous city in California, USA and the second most populous in the United States, after New York City. It has an area of , and is located in Southern California...
and
San DiegoSan Diego is the eighth-largest city in the United States and second-largest city in California. The city is located on the coast of the Pacific Ocean in Southern California, immediately adjacent to the Mexican border. The birthplace of California, San Diego is known for its mild year-round...
. The once-dynamic
Salton SeaThe Salton Sea is a shallow, saline, endorheic rift lake located directly on the San Andreas Fault, predominantly in California's Imperial Valley. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Imperial and Riverside counties in Southern California. Like Death...
and Colorado River ecosystems are now controlled by human water management. Because of the scarcity of water resources in the desert environment, these alterations have had substantial impacts on regional wildlife and habitats. In addition, portions of the region are experiencing substantial growth and development pressures, most notably the
Coachella ValleyCoachella Valley is a large valley landform in Southern California. The valley extends for approximately 45 miles in Riverside County southeast from the San Bernardino Mountains to the saltwater Salton Sea, the largest lake in California...
.
See also
- Yuma Desert
The Yuma Desert is a lower-elevation section of the Sonoran Desert in the southwestern United States and the northwest of Mexico. It is in the Salton basin. The desert contains areas of sparse vegetation and has notable areas of sand dunes. With an average rainfall less than 8 inches each...
- Chihuahuan Desert
The Chihuahuan Desert is a desert, and an ecoregion designation, that straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra...
- Deserts of California
- List of North American deserts
External links