Destination List > Joshua Tree National Park
Joshua Tree National Park
Photo by Henrique Pinto
Joshua Tree National Park is located in southeastern California, east of Los Angeles and San Bernardino, near Palm Springs. It is named for the Joshua trees (Yucca brevifolia) native to the Mojave Desert. Originally declared a national monument in 1936, Joshua Tree was redesignated as a national park in 1994 when the U.S. Congress passed the California Desert Protection Act. Encompassing a total of 790,636 acres (1,235.4 sq mi; 3,199.6 km2) – slightly larger than the state of Rhode Island – the park includes 429,690 acres (671.4 sq mi; 1,738.9 km2) of designated wilderness. Straddling San Bernardino and Riverside Counties, the park includes parts of two deserts, each an ecosystem whose characteristics are determined primarily by elevation: the higher Mojave Desert and the lower Colorado Desert. The Little San Bernardino Mountains traverse the southwest edge of the park.
The earliest known residents of the land in and around what later became Joshua Tree National Park were the people of the Pinto Culture, who lived and hunted here between 8000 and 4000 BCE. Their stone tools and spear points, discovered in the Pinto Basin in the 1930s, suggest that they hunted game and gathered seasonal plants. Later residents included the Serrano, the Cahuilla, and the Chemehuevi peoples. All three lived at times in small villages in or near water, particularly the Oasis of Mara in what non-aboriginals later called Twentynine Palms. They were hunter-gatherers who subsisted largely on plant foods supplemented by small game, amphibians, and reptiles while using other plants for making medicines, bows and arrows, baskets, and other articles of daily life. A fourth group, the Mojaves, used the local resources as they traveled along trails between the Colorado River and the Pacific coast. Today, small numbers of all four peoples live in the region near the park; the Twentynine Palms Band of Mission Indians, descendants of the Chemehuevi, own a reservation in Twentynine Palms.
The park's oldest rocks, Pinto gneiss among them, are 1.7 billion years old. They are exposed in places on the park's surface in the Cottonwood, Pinto, and Eagle Mountains. Much later, from 250 to 75 million years ago, tectonic plate movements forced volcanic material toward the surface at this location and formed granite. Erosion eventually exposed the harder rocks, gneiss and granite, in the uplands and reduced the softer rocks to debris that filled the canyons and basins between the ranges. The rock formations of Joshua Tree National Park owe their shape partly to groundwater, which eroded the corners and edges of blocks of stone, and to flash floods, which left piles of rounded boulders.