National Park of Joshua Tree

Location: California
Established: October 31, 1994
Size: 794,000 acres (303,110 hectares)

Two desert systems, the Mojave and the Colorado, abut within Joshua Tree, dividing California's southernmost national park into two arid ecosystems of profoundly contrasting appearance. The key to their differences is elevation.

The Colorado, the western reach of the vast Sonoran Desert, thrives below 3,000 feet (914 meters) on the park's gently declining eastern flank, where temperatures are usually higher. Considered "low desert," compared to the loftier, wetter, and more vegetated Mojave "high desert," the Colorado seems sparse and forbidding. It begins at the park's midsection, sweeping east across empty basins stubbled with creosote bushes. Occasionally decorated by "gardens" of flowering ocotillo and cholla cactus, it runs across arid Pinto Basin into a parched wilderness of broken rock in the Eagle and Coxcomb Mountains.

Many newcomers among the 1.3 million visitors who pass through each year are surprised by the abrupt transition between the Colorado and Mojave ecosystems. Above 3,000 feet, the Mojave section claims the park's western half, where giant branching yuccas thrive on sandy plains studded by massive granite monoliths and rock piles. These are among the most intriguing and photogenic geological phenomena found in California's many desert regions.

Joshua Tree's human history commenced sometime after the last ice age with the arrival of the Pinto people, hunter-gatherers who may have been part of the Southwest's earliest cultures. They lived in Pinto Basin, which though inhospitably arid today, had a wet climate and was crossed by a sluggish river some 5,000 to 7,000 years ago. Nomadic groups of Indians seasonally inhabited the region when harvests of pinyon nuts, mesquite beans, acorns, and cactus fruit offered sustenance. Bedrock mortars—holes ground into solid rock and used to pulverize seeds during food preparation—are scattered throughout the Wonderland of Rocks area south of the Indian Cove camping site.

A flurry of late 19th-century gold-mining ventures left ruins; some are accessible by hiking trails, or unmaintained roads suited only to four-wheel-drive vehicles and mountain bikes.