Joshua Tree National Park is located in southeastern California. Declared a U.S. National Park in 1994 when the US Congress passed the California Desert Protection Act (Public Law 103-433), it had previously been a U.S. National Monument since 1936. It covers a land area of 789,745 acres (319,598 ha). A large part of the park is designated to wilderness area; some 429,690 acres (173,890 ha). Straddling the San Bernardino County/Riverside County border, the park includes parts of two deserts, each an ecosystem whose characteristics are determined primarily by elevation. Below 3,000 feet (910 m), the Colorado Desert encompasses the eastern part of the park and features natural gardens of creosote bush, ocotillo, and cholla cactus. The Little San Bernardino Mountains run through the southwest edge of the park.
The higher, drier, and slightly cooler Mojave Desert is the special habitat of the Joshua tree (see Yucca brevifolia), from which the park gets its name. In addition to Joshua tree forests, the western part of the park includes some of the most interesting geologic displays found in California's deserts. The dominant geologic features of this landscape are hills of bare rock, usually broken up into loose boulders. These hills are popular amongst rock climbing and scrambling enthusiasts. The flatland between these hills is sparsely forested with Joshua trees. Together with the boulder piles and Skull Rock, the trees make the landscape otherworldly. Five Washingtonia fan palm oases in the park are the few areas where water occurs naturally and wildlife abounds.
A good place to view wildlife is at Barker Dam, a short hike from a parking area near Hidden Valley. Desert Bighorn Sheep sometimes stop by the dam for a drink. Tours of the Barker Dam area are available.
The rock formations of Joshua Tree National Park were formed 100 million years ago from the cooling of magma beneath the surface. Groundwater is responsible for the weathering that created the spheres from rectangular blocks.
Nine established campgrounds exist in the park, only two of which (Black Rock Canyon and Cottonwood) provide water and flush toilets. A fee is charged per night for each camping spot. Backcountry camping, for those who wish to backpack, is permitted with a few regulations.
There are several hiking trails within the park, many of which can be accessed from a campground. Shorter trails, such as the one mile hike through Hidden Valley, offer a chance to view the beauty of the park without straying too far into the desert. A section of the California Riding and Hiking Trail meanders for 35 miles through the western side of the park. The lookout point at Keys View, towards the south of the park, offers views of the Coachella Valley and Salton Sea.
The Geology Motor Tour is located in the south of the park and provides a self-guided tour for those visitors with a four-wheel drive vehicle. There are sixteen stops on the tour showcasing the region's geology.
Nature walks inside the park include:
Longer trails include:
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.
There are over 250 species of bird in the park including resident desert birds such as the Greater Roadrunner and Cactus Wren as well as Mockingbirds, Le Conte's Thrasher, Verdin and Gambel's Quail. There are also many transient species that may spend only one or two seasons in the park. Noted birding spots in the park include: fan palm oases, Barker Dam and Smith water Canyon. Queen Valley and Lost Horse Valley also provide good birding but with a different range of species because of the lack of water. These are often good places to see Ladder-backed Woodpecker and Oak Titmouse.
Of the park's total land area of 789,745 acres (319,598 ha), 429,690 acres (173,890 ha) are designated wilderness and managed by the National Park Service (NPS) in accordance with the Wilderness Act. The NPS requires registration for overnight camping at specific locations called registration boards. Other requirements include the use of a camp stove as open campfires are prohibited and employing Leave No Trace camping techiques (also known as "pack it in, pack it out"). Although bicycles are not allowed in wilderness areas, horses are, but a permit must be obtained in advance for travel in the backcountry.