The park includes parts of two deserts, each an ecosystem whose characteristics are determined primarily by elevation. Below 3,000 feet, the Colorado Desert encompasses the eastern part of the park and features natural gardens of creosote bush, ocotillo, and cholla cactus.
The higher, moister, and slightly cooler Mojave Desert is the special habitat of the Joshua tree (Yucca brevifolia). 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 a bonanza for rock climbing and scrambling enthusiasts. The flatland between these hills is sparsely forested with Joshua trees. Together with the boulder piles, the trees make the landscape otherworldly. Five fan palm oases in the park are the few areas where water occurs naturally and wildlife abounds.
Campgrounds in the park are few, mostly without a supply of water, so most visitors are required either to day-trip or stay at a hotel in a nearby town. Roads and hiking trails are also quite sparse. A dirt road in the south of the park showcases the region's geology. The lookout point at Keys View, also towards the south, offers views of the Coachella Valley and Salton Sea. Tours of an abandoned gold mine are available. The easiest ways to enjoy the park are to drive around and climb some boulder hills.
The park is extremely popular with rock climbers (who often refer to it as "J-Tree"). 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 literally 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 a very rough granite, there being no snow or ice to polish it as in places like Yosemite. Most climbs are singe pitch with all possible difficulty levels.Recreation in Joshua Tree National Park