Joshua Tree National Park is a United States National Park that is located in the Southern California Desert. The park encompasses nearly 800,000 acres of the Mojave and Colorado Deserts, conserving two separate desert ecosystems at different altitudes. The name of the park is derived from the distinctive Joshua Tree, a tall-growing variety of the yucca genus that grows prevalently within its boundaries.
The park is extremely popular with rock climbers (who often refer to it as "JT" if they are locals). It was originally a winter practice area while Yosemite Valley and other parts of the Sierra Nevada were snowbound, but later became an area of interest in its own right. There are thousands of named climbing routes, at all levels of difficulty. The routes are typically short, the rocks being rarely more than 70 m (230 ft) in height, but access is usually a short, easy walk through the desert, and it's possible to do a number of interesting climbs in a single day. The rocks are all composed of quartz monzonite, a very rough type of granite made even more so as there is no snow or ice to polish it as in places like Yosemite.
The main roads through the park are paved and easily accessible to passenger vehicles. Several dirt roads through the park may also be passable by automobiles, although conditions often require high-clearance, four-wheel drive vehicles; check at the ranger stations for current road conditions.
Water is available from all visitor centers and most campgrounds, and the Oasis Visitor Center also sells beverages. Towns, such as Twentynine Palms, located outside of the park borders offer additional options for refreshment.