At Joshua Tree National Park, the trees are merely the starting point for exploring the seemingly barren desert. Viewed from the roadside, the dry land only hints at hidden vitality, but closer examination reveals a giant mosaic of an ecosystem, intensely beautiful and complex. From lush oases teeming with life to rusted-out relics of man's attempts to tame this wilderness, from low plains of tufted cacti to mountains of exposed, gnarled rock, the park is much more than a tableau of the curious tree for which it's named.

The Joshua tree is said to have been given its name by early Mormon settlers (ca. 1850). Its upraised limbs and bearded appearance reminded them of the prophet Joshua leading them to the promised land. It's actually a treelike variety of yucca, a member of the agave family.

At Joshua Tree National Park, the peculiar tree reaches the southernmost boundary of its range. The park straddles two desert environments: The mountainous, Joshua tree-studded Mojave Desert forms the northwestern part of the park, while the hotter, drier, and lower Colorado Desert, characterized by a wide variety of desert flora such as cacti, ocotillo, and native California fan palms, comprises the park's southern and eastern sections. Between them runs the "transition zone," displaying characteristics of each.

The area's geological timeline stretches back almost 2 billion years. Eight million years ago, the Mojave landscape was one of rolling hills and flourishing grasslands; horses, camels, and mastodons abounded, with saber-toothed tigers and wild dogs filling the role of predator. Displays at the Oasis Visitor Center show how climactic, volcanic, and tectonic activity created the park's signature cliffs and boulders and turned Joshua Tree into the arid desert you see today. Human presence has been traced back nearly 10,000 years with the discovery of the Pinto culture, and you can see evidence of more recent habitation throughout the park in the form of American Indian rock art. Miners and ranchers began coming in the 1860s, but the boom went bust by the turn of the 20th century. Then Pasadena doctor James Luckie, treating World War I veterans suffering from respiratory and heart ailments caused by mustard gas, prescribed the desert's clean, dry air as a curative -- and modern interest in the area was born.

During the 1920s, a worldwide fascination with the desert emerged, and cactus gardens were much in vogue. Entrepreneurs hauled truckloads of desert plants into Los Angeles for quick sale or export, and souvenir hunters removed archaeological treasures. Incensed that the beautiful Mojave was in danger of being picked clean, Pasadena socialite Minerva Hoyt organized the desert conservation movement and successfully lobbied for the establishment of Joshua Tree National Monument in 1936.

In 1994, under provisions of the federal California Desert Protection Act, Joshua Tree was "upgraded" to national park status and expanded to nearly 800,000 acres.