Death Valley National Park is a national park in the U.S. states of California and Nevada located east of the Sierra Nevada, occupying an interface zone between the arid Great Basin and Mojave deserts in the United States. The park protects the northwest corner of the Mojave Desert and contains a diverse desert environment of salt-flats, sand dunes, badlands, valleys, canyons, and mountains. It is the largest national park in the lower 48 states and has been declared an International Biosphere Reserve..Wikipedia .