History of Joshua Tree National Park
The Joshua Tree area has a long history of human habitation, spanning over 5,000 years. The Chemehuevi people, who have a history spanning around four hundred years, settled in Southern California. Their domains encompassed the Pinto Basin and the Coxcomb Mountains in the eastern part of Joshua Tree National Park. However, in the late eighteenth century, they relocated to the Colorado River due to various factors. Unfortunately, conflict arose with the Mojave tribe in 1867, and as a result, the Chemehuevi were compelled to abandon the river and retreat. Seeking refuge, they returned to the temporarily abandoned Oasis of Mara, which had been vacated by Serrano survivors of a devastating smallpox outbreak. Over time, circumstances shifted, and the Chemehuevi gradually made their way back to the Colorado River, reclaiming their former territory. Nevertheless, a small contingent of the Chemehuevi community opted to stay behind in Twentynine Palms.
The vast Cahuilla territory stretched across vast expanses, spanning from the Colorado River all the way to the San Jacinto plain outside of Riverside. Just like the Serrano people, the Cahuilla resided in quaint villages situated near reliable water sources, skillfully utilizing the abundant resources of their land, which is believed to have encompassed both the western and southern regions of Joshua Tree National Park. As for the nomadic Chemehuevi, during the temperate seasons of spring and summer, they embarked on spontaneous hunting and gathering expeditions, establishing temporary abodes as their base camps. However, when the weather turned colder, the Chemehuevi convened in grand settlements and dwelled for extended periods within cozy winter abodes, ingeniously constructed with shallow pits as floors.
However, in the late 1920s, the development of new roads attracted land developers and cactus poachers to the region. This raised concerns for Minerva Hoyt, a resident of Pasadena who had a deep love for the desert plants. Recognizing the need for protection, she dedicated herself to preserving the area.
Thanks to Hoyt's tireless efforts, Joshua Tree National Monument was established in 1936, covering an impressive 825,000 acres. Initially, the monument was managed by the superintendent of Yosemite National Park until James Cole became the first designated superintendent in 1940. In 1950, a significant portion of the historic Oasis of Mara was transferred to the National Park Service by the Twentynine Palms Corporation.
However, in the same year, the monument's size was reduced by 265,000 acres to exclude certain mining properties. It wasn't until 1994 that Joshua Tree National Monument finally achieved park status as part of the Desert Protection Bill. This elevation in status also led to an expansion of the park by an additional 234,000 acres, aligning its boundaries with natural features and ecological units such as mountain ranges.
This change not only improved resource protection but also made boundary identification and monitoring more convenient. Additionally, the expansion provided essential habitat for desert bighorn sheep, enhancing the park's ecological diversity. Elevation within the park varies greatly, ranging from a low of 536 feet to a high of 5,814 feet at Quail Mountain.
In 1976, the U.S. Congress designated a total of 420,000 acres within Joshua Tree National Park as wilderness. This designation was made in addition to the existing 792,623 acres of the park, of which 591,624 acres are specifically designated wilderness areas.
The park serves as a vital habitat for a diverse range of wildlife. It is home to 813 higher plant species, 46 reptile species, 57 mammal species, and over 250 bird species. Unfortunately, some species within the park face threats to their survival. According to the federal register, the desert tortoise is listed as threatened, while the triple-ribbed milk vetch is classified as endangered. Another plant species, Parish's daisy, is also listed as threatened. In order to safeguard the park's biodiversity, the protection of 49 plant species of special concern has been prioritized.
Moreover, Joshua Tree National Park holds significant paleontological value. It currently features one paleontological area, with a potential for the existence of eight more. The park's commitment to preservation extends to its cultural heritage as well. Over 700 archeological sites, 88 historic structures, and 19 cultural landscapes are protected within its boundaries. The park's museum collection houses an impressive 230,300 distinctive items.
These facts illustrate the importance of Joshua Tree National Park as not only a natural wonderland, but also as a vital ecosystem with immense historical and cultural significance. For more information on the history of the Joshua Tree area, please visit nps.gov/jotr
Geology
The geologic landscape of Joshua Tree National Park has captivated countless visitors who marvel at the fascinating shapes of its rocks. Curiosity beckons as to how these formations came to be and what forces sculpted them. According to geologists, the genesis of this awe-inspiring landscape dates back more than 100 million years. Molten liquid, propelled by the ceaseless movement of Earth's crust, surged upwards and cooled beneath the surface. These subterranean intrusions, known as monzogranite, birthed the foundation of our modern topography.
Over time, the monzogranite developed a network of rectangular joints. One set of these joints, roughly aligned horizontally, is the product of eroded layers of gneiss, a type of rock, that once blanketed the landscape. Another set of joints runs vertically, mirroring the contact between the monzogranite and its surrounding rocks. The third set, also vertical, intersects the second set at steep angles, resulting in a captivating system of joints that manifests as rectangular blocks. Notable examples of this joint system can be observed at Jumbo Rocks, Wonderland of Rocks, and Split Rock within the park.
As groundwater permeated the fractures of the monzogranite, it gradually transformed select resilient mineral grains into soft clay, while concurrently loosening and freeing grains resistant to solution. Consequently, rectangular stones underwent a slow metamorphosis, evolving into spherical formations of hard rock enveloped by pliable clay housing loose mineral grains. Visualize the act of holding an ice cube under a faucet; the corners of the cube, exposed to the force of the water, gradually smooth out. Similarly, albeit on a grander scale and over the course of millions of years, this phenomenon transpired in Joshua Tree's wetter past. Following the advent of the current arid climate, flash floods began eroding the protective surface layer. Exposed to the elements, these immense weathered boulders settled atop one another, giving rise to the breathtaking rock piles that grace the landscape today.
When visitors explore the boulders at our site, they often become curious about the presence of "broken terrace walls" scattered throughout. These structures, known as dikes, are actually natural formations that formed when molten rock seeped into existing fractures in the monzogranite. As the molten rock cooled in these confined spaces, it transformed into light-colored aplite, pegmatite, and andesite dikes composed of quartz and potassium minerals. Interestingly, these dikes broke into uniform blocks upon reaching the surface, resembling the craftsmanship of a skilled stonemason.
While various processes contribute to the erosion of rock, it is primarily water that plays the most significant role, even in arid environments. Although wind does contribute, its long-term impact is relatively minimal when compared to the actions of water. However, the awe-inspiring sculpting of these rocks cannot solely be attributed to the present arid conditions. Rather, the landscape we see today is a collection of features inherited from previous times of higher rainfall and lower temperatures. These relict features serve as a testament to the dynamic nature of the Earth's geological history. For more information on the geology of Joshua Tree, please visit nps.gov/jotr.