The transition from the hot Sonoran Desert to the cooler and higher Great Basin is called the Mojave Desert. This arid region of southeastern California and portions of Nevada, Arizona, and Utah occupies more than 25,000 square miles.

On the northwestern boundary it extends from the Sierra Nevada range to the Colorado Plateau in the east; it abuts the San Gabriel-San Bernardino mountains in the southwest. Near the Great Basin-Mojave border lies Death Valley, the lowest point in North America and a national park.