The Mojave Desert (pronounced /moʊˈhɑːvi/ or /məˈhɑːvi/), (Hayikwiir Mat’aar in Mojave), locally referred to as the High Desert, occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, and northwestern Arizona, in the United States. Named after the Mohave tribe of Native Americans, it occupies well over 22,000 square miles (57,000 km2) in a typical Basin and Range topography.
The Mojave Desert’s boundaries are generally defined by the presence of Yucca brevifolia (including Joshua trees), considered an indicator species for the desert. The topographical boundaries include the Tehachapi together with the San Gabriel and San Bernardino mountain ranges. The mountain boundaries are quite distinct since they are outlined by the two largest faults in California: the San Andreas and the Garlock. The Great Basin shrub steppe lies to the north; the warmer Sonoran Desert (the Low Desert) lies to the south and east. The desert is believed to support between 1,750 and 2,000 species of plants.
The Mojave Desert receives less than 10 inches (250 mm) of rain a year and is generally between 3,000 and 6,000 feet (1,000 and 2,000 m) in elevation. The Mojave Desert also contains the Mojave National Preserve, as well as the lowest and hottest place in North America: Death Valley, where the temperature normally approaches 120°F (49°C) in late July and early August. Zion National Park, in Utah, lies at the junction of the Mojave, the Great Basin, and the Colorado Plateau. Despite its aridity, the Mojave (and particularly the Antelope Valley in its southwest) has long been a center of alfalfa production, fed by irrigation coming from groundwater and (in the 20th century) from the California Aqueduct.
The Mojave is a desert of temperature extremes and four distinct seasons. Winter months bring temperatures dipping to below 20 °F (-7 °C) on valley floors, and below 0 °F (-18 °C) at higher elevations. Storms moving from the Pacific Northwest can bring rain and snow across the region — more often, the rain shadow created by the Sierra Nevada as well as mountain ranges within the desert such as the Spring Mountains bring only clouds and wind. In longer periods between storm systems, winter temperatures in valleys can approach 80 °F (27 °C).
Spring weather continues to be influenced by Pacific storms, but rainfall is more widespread and occurs less frequently after April. By early June, it is rare for another Pacific storm to have a significant impact on the region’s weather, and temperatures after mid-May are normally above 90 °F (32 °C) and frequently above 100 °F (38 °C).