California Desert
California has more desert than any other US state. The Mojave Desert in the east, the Colorado Desert (a sub-section of the Sonoran) in the southeast, and the Great Basin in the northeast all reach into California. Together they cover roughly a quarter of the entire state. The California deserts include the hottest place on Earth (Death Valley), the strange Joshua Trees, the Salton Sea, and the deserts that lie just east of Los Angeles and San Diego.
- CountryUnited StatesIn the western US
- % of Californiaapprox. 25%Eastern and southeastern parts
- Hottest placeDeath Valley56.7 °C world record
- Famous parksJoshua Tree, Death Valley, Anza-BorregoAnd Mojave National Preserve
- Iconic plantJoshua treeOnly in the Mojave portion
- Strange lakeThe Salton SeaAn accidental salt lake from 1905
California's deserts compared
The Mojave is the biggest desert in California by a long way. The smaller Colorado Desert (a sub-section of the wider Sonoran) is in the southeast.
What are the California deserts?
California's desert lies in the rain shadow of the high mountains that run down the state's eastern side: the Sierra Nevada, the Transverse Ranges and the Peninsular Ranges. The west sides of these mountains catch Pacific storms and stay forested and fertile (the famous Californian coast and farming valleys). The east sides are bone dry. The desert begins right at the eastern foot of the mountains and continues across into Nevada and Arizona.
The four desert regions
- Death Valley and the Mojave proper in the central east. Death Valley is the lowest, hottest and driest part. Joshua Tree National Park is in the southern Mojave.
- The Colorado Desert in the southeast, around the Salton Sea and the Anza-Borrego Desert State Park. This is a low-elevation hot desert with palms, mesquite and ocotillo.
- The Great Basin reaches into the far northeast around the Modoc Plateau.
- Owens Valley and the high country east of the Sierra Nevada is technically Great Basin but feels like its own desert, with the high White Mountains rising on its east side.
The Salton Sea
The Salton Sea is one of California's strangest features. In 1905, engineers digging an irrigation channel from the Colorado River accidentally let the entire river flow into a low-lying area called the Salton Sink for 18 months before they could plug the leak. The result was a vast new inland sea, approx. 64 km long, the largest lake in California.
The sea was originally a tourist attraction (with resorts, fishing camps and yacht clubs), but it has been dying for decades. The water has nowhere to go except by evaporation, and the salts and farm chemicals have steadily concentrated. The water is now saltier than the ocean. Fish die-offs are common. The shrinking lake exposes toxic dust that blows into nearby communities. Various rescue plans have been proposed but the sea's future is uncertain.
Joshua Tree National Park
One of the most popular desert parks in the US is Joshua Tree National Park, set up to protect the iconic Joshua tree at the meeting point of the Mojave and Colorado deserts. The park has surreal rock piles, dark night skies (it is a designated International Dark Sky Park) and the strange spiky Joshua trees themselves. About 3 million people visit per year.
Deeper dive: the Sierra Nevada rain shadow, Owens Lake dust and desert preservation
California's desert exists because of the Sierra Nevada rain shadow. The Sierra Nevada is a steep mountain range running north-south for approx. 650 km along eastern California, with peaks reaching over 4,300 metres. Moist Pacific air rises over the Sierra and dumps enormous quantities of rain and snow on the western slopes. By the time the air descends on the eastern side, it has lost most of its moisture and is warmer (because falling air compresses and heats up). The result is one of the most dramatic climate gradients in the world: snowy peaks and forests on the west side, sagebrush desert on the east side, sometimes within sight of each other.
One of the most dramatic environmental disasters in California history happened at Owens Lake, on the east side of the Sierra Nevada. Owens Lake was a large freshwater lake fed by the Owens River and a key stop for migrating birds. In 1913, the Los Angeles Aqueduct began diverting the Owens River to supply water to growing Los Angeles 350 km away. Within 13 years, Owens Lake was dry. The exposed lakebed became the largest source of dust pollution in North America, blowing toxic alkaline dust into the surrounding communities. After decades of lawsuits, Los Angeles is now required to control the dust by spreading water and gravel across the lake bed. The fight inspired the famous film Chinatown.
California's deserts are surprisingly well protected. Three large national parks (Death Valley, Joshua Tree, Mojave National Preserve), several large state parks (notably Anza-Borrego, the second-largest state park in the contiguous US), and a 1994 California Desert Protection Act together protect millions of acres. The deserts have been a popular escape for Hollywood and California city dwellers for over a century, and several generations of conservationists, artists and writers have campaigned for their preservation. The continuing threats are climate change (which is making the deserts hotter and drier), groundwater pumping, off-road vehicle damage, and the constant expansion of solar power facilities, which need vast areas of flat land and are sometimes built on sensitive desert habitat.
The country is the United States. The biggest of California's deserts is the Mojave.