There are four major deserts in the United States. They are all located in the western portion of the country and are defined to be areas that receive less than ten inches of precipitation (rain, snow, etc.) a year.
Great Basin Desert
The Great Basin Desert is generally considered the largest of the four US deserts. Although we usually think of deserts as being hot, the Great Basin Desert is often very cold and most of the precipitation that falls in the desert is snow. Much of the desert is at high altitudes of 3,000 to 6,000 feet or more.
The Great Basin Desert is located between the Sierra Nevada Mountains and the Rocky Mountains. It is mostly in the state of Nevada, but also parts of California, Idaho, Utah, and Oregon. The region gets so little rain because the Sierra Nevada Mountains form a shield from the winds from the Pacific Ocean, preventing moisture from the air into the region.
Common plants in the desert include sagebrush and shadscale. One of the more unique plants to grow here is the bristlecone pine. This tree is the oldest known living organism in the world. Some of these trees are estimated to have lived for over 5,000 years.
Chihuahuan Desert
The Chihuahuan Desert is located along the border between Mexico and the United States. It occupies portions of southwest Texas, southern New Mexico, and southeast Arizona. The largest part of the desert is in Mexico.
The dominant plant found in the Chihuahuan Desert is the creosote bush. Other plants include yuccas, agaves, prickly-pear cactuses, and various grasses. The Rio Grande River cuts through the desert on its way to the Gulf of Mexico. The Big Bend National Park is also part of Chihuahuan Desert, protecting over 800,000 acres of the desert's plant and wildlife.
Sonoran Desert
The Sonoran Desert is located in Southern California, Arizona, and Mexico. There are two major rivers that flow through the desert: the Colorado River and the Gila River. There are mountains in the desert with wide valleys. The valleys can get extremely hot during the summer.
The desert is perhaps most famous for the saguaro cactus. This cactus can grow to be over 60 feet tall with branches that can sometimes look like arms. Other plants that are common to the Sonoran Desert include the Cholla cactus, beavertail cactus, creosote bush, indigo bush, and the Mormon tea bush. A wide variety of animals live here including lizards, bats, jackrabbits, sparrows, snakes, turtles, and owls.
Saguaro cacti in the Sonoran Desert
Sub-deserts within the Sonoran Desert include the Colorado Desert, Yuma Desert, Tonopah Desert, and the Yuha Desert.
Mojave Desert
The Mojave Desert is located in the southwest United States in California, Nevada, and Arizona. It sits between the Great Basin Desert to the north and the Sonoran Desert to the south.
The desert has extreme elevations which range from a high point of 11,049 feet at Telescope Peak to a low point of 282 feet below sea level at Death Valley. Along with the extremes in elevations comes a wide range of temperatures. The higher elevations can become extremely cold, especially at night. Death Valley, on the other hand, is the hottest place in the United States with a world record high temperature of 134 degrees F and an average annual rainfall of less than 2 inches.
The Mojave Desert is famous for the Joshua Tree (scientific name is yucca brevifolia). Much of the land is sparsely covered with grasses and the creosote bush. The desert is home to a variety of animals including lizards, snakes, the Mojave ground squirrel, rabbits, pronghorns, scorpions, and the kangaroo rat.
