, a ridgeline wilderness area on the eastern border of the river proper, 30 miles north of
Yuma–
Winterhaven. A
buckhorn cholla cactus is in foreground;
creosote bush scrubland on hillsides. Some of the highest air temperatures in North America are recorded in the LCRV, rivaling
Death Valley; specifically
Bullhead City,
Lake Havasu City,
Laughlin,
Needles,
Yuma, or the southeastern deserts of California, west of the Colorado River where extreme heat is the main summertime weather feature. Worldwide, only deserts in Africa and in the
Middle East are hotter. The LCRV is defined by three deserts. The
Mojave Desert is in southeast California, southern Nevada, and northwest Arizona. South of the Mojave the
Sonoran Desert spans both sides of the Colorado River. The Lower Colorado River Valley is in the western part of the Sonoran Desert, which is called the
Colorado Desert. the Sonoran Desert region proper extends from areas west of the river, and then southeastwards to southeast Arizona, south along the eastern side of the
Baja Peninsula cordillera to
Baja California Sur, and southeast
Sonora state, Mexico to the northern border of neighboring
Sinaloa. The LCRV extends about from Hoover Dam to the
Colorado River Delta. The Sonoran Desert itself is more than twice as extensive north-to-south, and about in width. Two species,
desert ironwood and the
lesser long-nosed bat, have geographic ranges identical to the Sonoran Desert, and are
indicator species of the Sonoran Desert region. The spring flowering of ironwood, and the bat species migration arrivals also become indicators of annual or multi-year climate trends for regions of the Sonoran Desert.
Fauna Flora The Lower Colorado River Valley has unique plant communities because it is the most arid part of the desert and it has the highest temperatures, in excess of during the summer. The low humidity means that most plants must have mechanisms that deal with severe water loss through evaporation. The soils tend to be typical
desert soils, coarse and without well-developed
organic horizons, and plants can only obtain soil water during and very soon after the infrequent rains. ==List of major cities and communities==