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20-528: The Colorado Desert is a subregion of the larger Sonoran Desert , covering about 7 million acres (2.8 million ha; 28,000 km). The desert occupies Imperial County , parts of San Diego and Riverside counties, and a small part of San Bernardino County in California , United States, as well as the northern part of Mexicali Municipality in Baja California , Mexico. Most of

40-450: Is a U.S. National Wildlife Refuge in the floodplain of the lower Colorado River between Arizona and California and surrounded by a fringe of desert ridges and washes. The refuge encompasses both the historic Colorado River channel as well as a channelized portion constructed in the late 1960s. Along with these main waterbodies, several important backwaters are home to many wildlife species that reside in this Yuma Desert portion of

60-530: Is a continental landmass comprising the continents of North America and South America . [REDACTED] Africa [REDACTED] Antarctica [REDACTED] Asia [REDACTED] Australia [REDACTED] Europe [REDACTED] North America [REDACTED] South America [REDACTED] Afro-Eurasia [REDACTED] Americas [REDACTED] Eurasia [REDACTED] Oceania Cibola National Wildlife Refuge Cibola National Wildlife Refuge

80-694: 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, aquatic 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, ephemeral and perennial streams, and desert riparian vegetation communities dominated by cottonwood , willow , and non-native tamarisk . Two of

100-752: Is focusing on the  United Nations geoscheme , which is a changing, constantly updated, UN tool based on specific political geography and demography considerations relevant in UN statistics. The Statistics Division of the United Nations (UN) is in charge of the collection, processing, and dissemination of statistical information for the UN. In 1999, it developed a system of macro-geographical (continental) regions, subregions, and other selected economic groups to report advances towards achieving numerous millennial development goals worldwide. These statistical divisions were devised for statistical purposes and

120-479: Is used for carrying out statistical analysis. The division's first publication was the book World's Women 2000: Trends and Statistics in 2000. According to the UN, the assignment of countries or areas to specific groupings is for statistical convenience and does not imply any assumption regarding political or other affiliation of countries or territories. The following is a non-exhaustive list of subregions, arranged alphabetically by region (i.e., by continent); in

140-638: The Gulf of California to the south, and are often active in the summer monsoons . These include remnants of Pacific hurricanes, storms from the southern tropical jetstream , and the northern Intertropical Convergence Zone . The region's terrestrial habitats include creosote bush scrub; mixed scrub , including yucca and cholla cactus ; desert saltbush ; sandy soil grasslands ; and desert dunes . 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

160-618: The Sonoran Desert . Because of the river's life-sustaining water, wildlife here survive in an environment that reaches 120 °F (49 °C) in the summer and receives an average of only 2 inches (5.1 cm) of rain per year. The Refuge is one of the last major stop overs of the Pacific Flyway for migratory birds. Over 250 species of birds have been identified at Cibola NWR, including Canada geese , golden eagles , great blue herons , sandhill cranes , snowy egrets , and

180-706: 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 . Consequently, the region is subject to earthquakes , and 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 almost never experiences frost. In addition,

200-456: 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 usually has only winter rains. 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

220-526: The Colorado Desert lies at a relatively low elevation, below 1,000 ft (305 m), with the lowest point of the desert floor at 275 ft (84 m) below sea level , at the Salton Sea . Although the highest peaks of the Peninsular Ranges reach elevations of nearly 10,000 ft (3,048 m), most of the region's mountains do not exceed 3,000 ft (914 m). In this region,

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240-624: The Colorado Desert. 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, and can be found in the San Jacinto, Santa Rosa, and Little San Bernardino mountains, in the canyons of Anza-Borrego Desert State Park , and along the San Andreas Fault in the Coachella Valley . The only palm native to California, Washingtonia filifera (desert fan palm), grows at

260-415: The UN geoscheme, higher-level, macro-geographical regions are arranged to the extent possible according to continents. Sequence used in the list (not all criteria are applied to each continent): Afro-Eurasia is a continental landmass comprising the continents of Africa , Asia , and Europe . Eurasia is a continental mainland comprising the continents of Asia and Europe . The Americas

280-758: 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 trees. Common desert wildlife include mule deer , bobcat , desert kangaroo rat , cactus mouse , black-tailed jackrabbit , Gambel's quail , and 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 , and California leaf-nosed bat . The best place to spot wildlife

300-493: The endangered southwestern willow flycatcher . Other species that inhabit the area include mule deer , Gambel's quail , bobcat , and coyote . Cibola NWR undertakes major projects annually including the conservation of a desert pupfish population, one of three that exist in Arizona. Invasive species removal enhances the natural riparian habitat and provides hunting opportunities. In return, populations are regulated, and

320-612: 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 (desert lily), Nolina bigelovii (Bigelow's nolina), and Peucephyllum schottii (desert fir). The Colorado Desert is one of the least-populous regions in California, but human activities have had substantial impacts on

340-424: 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

360-570: The region's most significant aquatic systems are the Salton Sea and 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 , and 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 ecological communities found only in

380-507: 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 Valley . Subregion A subregion is a part of a larger geographical region or continent . Cardinal directions are commonly used to define subregions. There are many criteria for creating systems of subregions; this article

400-417: The water diversions and flood control measures along the Colorado River . These measures have dramatically altered the region's hydrology by redistributing the region's water supply to large expanses of irrigated agriculture and metropolitan coastal areas such as Los Angeles and San Diego . The once-dynamic Salton Sea and Colorado River ecosystems are now controlled by human water management. Because of

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