Joshua Tree National Park is located in south-eastern California. Declared a U.S. National Park in 1994, it had previously been a U.S. National Monument since 1936. It includes over 1,234 mi² (3,196 km²) of land. A large part of the park is designated to wilderness area; some 914 mi² (2,367 km²). The Joshua tree (Yucca brevifolia) is a monocotyledonous tree native to southwestern North America, in the states of California, Arizona, Utah and Nevada.  Confined mostly to the Mojave Desert between 400-1,800 m (2,000-6,000 feet), they thrive in the open grasslands of Queen Valley and Lost Horse Valley in Joshua Tree National Park. Viewed from the road, this desert park only hints at its vitality. Closer examination reveals a fascinating variety of plants and animals that make their home in this land shaped by strong winds, unpredictable torrents of rain, and climatic extremes. Dark night skies, a rich cultural history, and surreal geologic features add to the attraction of this place. Come see for yourself!

As seen at http://www.nps.gov/ and http://en.wikipedia.org/wiki/Joshua_Tree_National_Park