Joshua Tree National 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.[6] Their stone tools and spear points, discovered in the Pinto Basin in the 1930s, suggest that they hunted game and gathered seasonal plants, but little else is known about them.[6] 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 subsisted largely on plant foods supplemented by small game, amphibians, and reptiles while using other plants for making medicines, bows, arrows, baskets, and other articles of daily life.[7]

A fourth group, the Mojaves, used the local resources as they traveled along trails between the Colorado River and the Pacific coast. In the 21st century, 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.[8]

In 1772, a group of Spaniards led by Pedro Fages made the first European sightings of Joshua trees while pursuing native converts to Christianity who had run away from a mission in San Diego. By 1823, the year Mexico achieved independence from Spain, a Mexican expedition from Los Angeles, in what was then Alta California, is thought to have explored as far east as the Eagle Mountains in what later became the park. Three years later, Jedediah Smith led a group of American fur trappers and explorers along the nearby Mojave Trail, and others soon followed. Two decades after that, the United States defeated Mexico in the Mexican–American War (1846–48) and took over about half of Mexico's original territory, including California and the future parkland.[9]

In 1870, white settlers began grazing cattle on the tall grasses that grew in the park. In 1888, a gang of cattle rustlers moved into the region near the Oasis of Mara. Led by brothers James B. and William S. McHaney, they hid stolen cattle in a box canyon at Cow Camp.[10] Throughout the region, ranchers dug wells and built rainwater catchments called "tanks", such as White Tank and Barker Dam.[11]

In 1900,[12] C. O. Barker, a miner and cattleman, built the original Barker Dam, later improved by William "Bill" Keys, a rancher.[13] Grazing continued in the park through 1945.[11] Barker Dam was added to the National Register of Historic Places (NRHP) in 1975.[12]

Between the 1860s and the 1940s, miners worked about 300 pit mines, mostly small, in what later became the park.[14] The most successful, the Lost Horse Mine, produced gold and silver worth about $5 million in today's currency.[15] Johnny Lang and others, the original owners of the Lost Horse Mine, installed a two-stamp mill to process ore at the site, and the next owner, J.D. Ryan, replaced it with a 10-stamp steam-powered mill. Ryan pumped water from his ranch to the mill and cut timber from the nearby hills to heat water to make steam. Most of the structures associated with the mine fell apart, and for safety reasons the National Park Service plugged the mine, which had collapsed.[15]

The Desert Queen Mine on Keys' Desert Queen Ranch was another productive gold mine.[14] In the early 1930s, Keys bought a gasoline-powered two-stamp mill, the Wall Street Mill, and moved it to his ranch to process ore.[16] The ranch and mill were added to the NRHP in 1975[16][17] and the mine in 1976.[18] Some of the mines in the park yielded copper, zinc, and iron.[14]

A grove of namesake Joshua trees at Joshua Tree National Park

On August 10, 1936, after Minerva Hoyt and others persuaded the state and federal governments to protect the area, President Franklin D. Roosevelt used the power of the 1906 Antiquities Act to establish Joshua Tree National Monument,[19] protecting about 825,000 acres (1,289.1 sq mi; 3,338.7 km²).[20] In 1950, the size of the park was reduced by about 290,000 acres (453.1 sq mi; 1,173.6 km²) to open the land to more mining.[21] The monument was redesignated as a national park on October 31, 1994, by the Desert Protection Act, which also added 234,000 acres (365.6 sq mi; 947.0 km²).[22] In 2019, the park expanded by 4,518 acres (7.1 sq mi; 18.3 km²) under a provision included in the John D. Dingell, Jr. Conservation, Management, and Recreation Act.[23][24]

The Mojave Desert Land Trust (MDLT) has conserved 10,290 acres (4,160 ha) within the park. These inholdings were private ownership within the national park that they were able to purchase. They also acquire private properties bordering federally protected properties. MDLT has sold 25,801 acres (10,441 ha) of acquired private property to the national park service which is more than any other similar organization.[25]

According to the A. W. Kuchler U.S. Potential natural vegetation types, Joshua Tree National Park has two categories, a creosote bush potential vegetation type with a desert shrubland potential vegetation form in most of the area, and a juniper/pinyon pine potential vegetation type with a Great Basin montane forest/southwest forest potential vegetation form on the higher elevations of the western side of the park.[26]

Dollarjoint pricklypear near Skull Rock in Joshua Tree

Chuckwalla cholla in Joshua Tree

The higher and cooler Mojave Desert is the special habitat of Yucca brevifolia, the Joshua tree for which the park is named. It occurs in patterns from dense forests to distantly spaced specimens. In addition to Joshua tree forests, the western part of the park includes some of the most interesting geologic displays found in California's deserts. The dominant geologic features of this landscape are hills of bare rock, usually broken up into loose boulders. These hills are popular among rock climbing and scrambling enthusiasts. The flatland between these hills is sparsely forested with Joshua trees. Together with the boulder piles and Skull Rock, the trees make the landscape otherworldly. Temperatures are most comfortable in the spring and fall, with an average high/low of 85 and 50 °F (29 and 10 °C), respectively. Winter brings cooler days, around 60 °F (16 °C), and freezing nights. Snows occur occasionally at higher elevations. Summers are hot, over 100 °F (38 °C) during the day and not cooling much below 75 °F (24 °C) until the early hours of the morning.[27]

Joshua trees dominate the open spaces of the park, but in among the rock outcroppings are piñon pine, California juniper (Juniperus californica), Quercus turbinella (desert scrub oak), Quercus john-tuckeri (Tucker's oak), Quercus cornelius-mulleri (Muller's oak),[28] Cylindropuntia chuckwallensis (chuckwalla cholla), and Opuntia chlorotica (dollarjoint pricklypear).[29]

These communities are under some stress, however, as the climate was wetter until the 1930s, with the same hot and dry conditions that provoked the Dust Bowl affecting the local climate. These cycles were nothing new, but the original vegetation did not prosper when wetter cycles returned. The difference may have been human development. Cattle grazing took out some of the natural covers and made it less resistant to the changes.

There are fewer Joshua tree seedlings surviving in the park.[30] It is forecasted that by 2099, under the high emission scenario, the park will increase in temperature by 8 °F. This would make most of the national park unsuitable for Joshua tree growth. Under the low emission scenario, 80% of suitable Joshua tree habitat could be lost.[30]

The desert tortoise population has decreased due to habitat loss and climate change. Lizards in the park are also at risk. Bird species have declined 43% according to studies conducted in 1908–1968 and 2013–2016.[30]

Cholla Cactus Garden in 2022

Below 3,000 feet (910 m), the Colorado Desert encompasses the eastern part of the park and features habitats of creosote bush scrub, ocotillo, desert saltbush, and mixed scrub including yucca and cholla cactus (Cylindropuntia bigelovii). Some areas of such cactus are dense enough to appear as natural gardens. The lower Coachella Valley is on the southeastern side of the park with sandy soil grasslands and desert dunes.

The only palm native to California, the California fan palm (Washingtonia filifera), occurs naturally in five oases in the park, rare areas where water occurs naturally year-round, and all forms of wildlife abound.[5]

Invasive plants such as cheat grass and red brome contribute to the worsening of wildfires. During wetter periods fills in below and among the pines and oak. In drier times, they die back but do not quickly decompose. This makes wildfires hotter and more destructive, which kills some of the trees that would have otherwise survived. When the area regenerates, these non-native grasses form a thick layer of turf that makes getting a roothold harder for the pine and oak seedlings.

Fountain grass was introduced to the park in the 1990s. This grass competes with native grasses for water and nutrients.[31]

According to the Köppen climate classification system, Joshua Tree National Park has a hot desert climate (BWh). According to the United States Department of Agriculture, the plant hardiness zone at the Cottonwood Visitor Center at 3081 ft (939 m) elevation is 8b, with an average annual extreme minimum temperature of 19.8 °F (−6.8 °C).[32]

Joshua Tree is becoming hotter and drier due to climate change.[30] From 1895 to 2016 the annual precipitation has dropped by 39% and the annual temperature has increased by 3 °F.[30] Because of the hotter and drier conditions, there are more wildfires in the park.

A Jumbo Rocks Campground site

Nine established campgrounds exist in the park, two of which (Black Rock Campground and Cottonwood Campground) provide water and flush toilets. A fee is charged per night for each camping spot.[37] Reservations are accepted at Black Rock Campground, Cottonwood Campground, Indian Cove Campground, and Jumbo Rocks Campground for October through May, while the other campgrounds are first-come, first-served. Backcountry camping, for those who wish to backpack, is permitted with a few regulations.[38]

Several hiking trails are within the park, many of which can be accessed from a campground. Shorter trails, such as the one-mile hike through Hidden Valley, offer a chance to view the beauty of the park without straying too far into the desert. A section of the California Riding and Hiking Trail meanders for 35 miles (56 km) through the western side of the park.[39] The lookout point at Keys View, towards the south of the park, offers views of the Coachella Valley, the Salton Sea, the San Andreas Fault, the Santa Rosa Mountains, and the city of Palm Springs.[40]

Nature walks inside the park include:

• Hidden Valley
• Indian Cove
• Cholla Cactus Garden

Longer trails include:

• Boy Scout Hiking and Equestrian Trail[41]
• Contact Mine
• Fortynine Palms Oasis
• Lost Horse Mine
• Lost Palms Oasis
• Ryan Mountain
• Warren Peak
• California Riding and Hiking Trail[42]

Due to graffiti on at least 17 sites on trails, officials have closed them to the public. The closed sites include Native American sites, Rattlesnake Canyon, and Barker Dam. They blame the increase in vandalism on the increased use of social media.[43]

Climbing the Old Woman Rock

The park is popular with rock climbers and was originally a winter practice area while Yosemite Valley and other parts of the Sierra Nevada were snowbound, but later became an area of interest in its own right. Its thousands of named climbing routes contain all levels of difficulty. The routes are typically short, the rocks being rarely more than 230 ft (70 m) in height, but access is usually a short, easy walk through the desert, and doing several interesting climbs in a single day is possible. The rocks are all composed of quartz monzonite, a very rough type of granite, made even more so as no snow or ice polishes it as in places such as Yosemite.

Some routes are permanently closed, while others are closed temporarily to protect sensitive wildlife in certain seasons. Climbing and bouldering routes that are permanently closed include Energy Crisis, the Schwarzenegger Wall, Zombie Woof Rock, the Maverick Boulder formation, Pictograph Boulder, Shindig, Lonely Stones Area #3, and the Shipwreck formation, Indian Wave Boulders (except for Native Arete), and Wormholes. As of March 14, 2018, seasonal closures include the Slatanic Area, Towers of Uncertainty, Patagonia Pile, and Jerry's Quarry.[44]

Pinto Basin Road at twilight, view towards the Colorado Desert portion of the park

The total visitors more than doubled from 2013 to 2019. Awareness of the wildflower bloom in the spring has brought increased visitation.[45]

The paved main road allows visitors to drive to major attractions and through the park. The unpaved roads may require a vehicle with high ground clearance, and four-wheel drive. An example is the Geology Tour Road in the center of the park. Visitors with a four-wheel-drive vehicle can use this road for a self-guided tour with stops that describe the region's geology.[46]

A greater roadrunner

More than 250 bird species inhabit or visit the park, including resident desert birds such as the greater roadrunner, cactus wren, northern mockingbird, LeConte's thrasher, verdin, and Gambel's quail. About 78 species nest and raise their young within the park. Many migrating species spend only a short time feeding and resting at Joshua Tree, mainly in the winter, as the park lies along an inland stretch of the Pacific Flyway. Other species descend from their usual habitats in the mountains to escape winter snow.[47]

Birdwatching spots include fan palm oases, the Barker Dam, and Smith Water Canyon. Queen Valley and Lost Horse Valley also provide good birdwatching, with a different range of species due to the lack of water, including the ladder-backed woodpecker and oak titmouse. A USGS bird checklist from 2006 contained 239 species in the park.[48]

The park offers naturally dark views of the night sky, as seen in this 30-second exposure showing the Milky Way behind a silhouetted Joshua tree (July 2017)

Joshua Tree is a popular observing site in Southern California for amateur astronomy and stargazing,[49] along with nearby Anza-Borrego Desert State Park. The park's elevation and dry desert air, along with the relatively stable atmosphere in the region, often make for excellent seeing conditions.

The park is well known for its naturally dark night skies, which are far away from and largely free of the light pollution typical in urban areas.  In 2017, the International Dark-Sky Association designated Joshua Tree a Dark Sky Park.[50]

On clear nights around new moon, the sky darkness of Joshua Tree is rated a class 2–4 on the Bortle scale.[51][52] This ranges from an "average dark sky" (class 2) in the easternmost region of the park to a sky quality typical of a rural/suburban transition (class 4) in the western regions near Palm Springs.[52][53] In the easternmost regions of the park, visitors with optimal vision can expect to see the Andromeda (M31) and Triangulum (M33) galaxies with unaided eyes. The central Milky Way appears highly structured to the naked eye from this site, and zodiacal light appears as a faint yellowish glow when visible.[53] In the western regions of the park, the Andromeda Galaxy is still visible, and only the brightest structures around the Galactic Center of the Milky Way can be distinguished; zodiacal light is visible halfway to the zenith.[53]

• Dilsaver, Lary M. (March 2015). Joshua Tree National Park: A History of Preserving the Desert (PDF). National Park Service. OCLC 912308073. Retrieved July 4, 2017.
• Eggers, Margaret (2004). Mining History and Geology of Joshua Tree National Park. San Diego Association of Geologists. ISBN 978-0-916251-70-3.
• Kaiser, James (2010). Joshua Tree: The Complete Guide (4th ed.). Destination Press. ISBN 978-0-9825172-3-9.
• Zarki, Joseph W. (2015). Images of America: Joshua Tree National Park. Charleston, South Carolina: Arcadia Publishing. ISBN 978-1-4671-3281-7.