The Mojave desert (spelled Mohave if you're in Arizona) is the most temperate and most heavily settled of the four US deserts. It exists as a kind of midpoint between the Colorado to the south and the Great Basin to the north, defined as much by tradition as by ecology.
The Mojave is sometimes divided into the Northern and Southern Mojave deserts, with the Northern Mojave lying north of Las Vegas, NV and the Southern Mojave lying south of Las Vegas.
It encompasses more than 25,000 square miles, bordered on the northwest by the Sierra Nevada, by the San Gabriels and San Bernardinos on the southwest, and by the Colorado Plateau on the east. To the north lies the Great Basin, a higher, cooler desert, and to the south lies the Colorado Desert section of the Sonoran Desert.
The Mojave is characterized by basins and ranges. Basins are differentiated from valleys in that they do not have regular outlets for flowing water. Thus, basins accumulate minerals and gravel which is swept into them during periods of rainfall. Mojave minerals include borax and salt.
Another feature common in parts of the Mojave is pink and tan granitic monzonite. Monzonite is an igneous rock that tends to crack in both horizontal and vertical planes after cooling and when pressure from overlying rocks is relieved. When the monzonite is eventually exposed, these cracks cause weathering which in turn leads to vertical columns and piles of rounded boulders standing alone on the desert. These columns are called Inselbergs.
Alluvial fans (material washed out at the mouth of canyons), bajadas (connected alluvial fans) and arroyos (steep canyons) are also characteristic of the Mojave.
Yearly precipitation in the Mojave averages less than five inches, most of which occurs during fall monsoons and in the winter. Summer temperatures reach 120+, but in the winter, freezing temperatures are common. The Mojave is typically windy, especially in the summer.
Plant and animal life:
Perhaps the most easily recognized and abundant Mojave plant is the creosote bush. Joshua trees also occur almost exclusively in the Mojave, although there is some range overlap to the east, and the Mojave continues farther to the north than the range of the Joshua tree. Mojave yucca, desert saltbush, Mormon tea, bladderpod, smoketree, and blackbrush are other common plants.
The Mojave is also home to the threatened desert tortoise, coyotes, bobcats, deer, bighorn sheep, rabbits and hares, ground squirrels and mice, and a wide variety of birds.