Joshua Tree??™s nearly 800,000 acres were set aside to protect the unique assembly of natural resources brought together by the junction of three of California??™s ecosystems. The Colorado Desert, a western extension of the vast Sonoran Desert, occupies the southern and eastern parts of the park. It is characterized by stands of spike-like ocotillo plants and “jumping” cholla cactus. The southern boundary of the Mojave Desert reaches across the northern part of the park. It is the habitat of the park??™s namesake: the Joshua tree. Extensive stands of this peculiar looking plant are found in the western half of the park. Joshua Tree??™s third ecosystem is located in the western most part of the park above 4,000 feet. The Little San Bernardino Mountains provide habitat for a community of California juniper and pinyon pine.