Great Basin Desert
The Great Basin Desert covers most of Nevada and parts of Utah, Oregon, Idaho and California. It is the largest desert in the United States and one of the few "cold deserts" in the world: winter temperatures regularly drop below freezing, and snow is common. The Great Basin is a strange landscape of long parallel mountain ranges separated by flat desert valleys, with no rivers reaching the sea from anywhere in the entire region.
- Areaapprox. 492,000 km²Largest US desert
- CountryUnited StatesNevada plus Utah, Oregon, Idaho, California
- TypeCold desertSnow is common in winter
- Elevation1,000 to 4,000 mHigh desert with mountains in the middle
- Famous lakeGreat Salt LakeA vast salty inland sea
- Oldest treeBristlecone pineOver 4,800 years old
The Great Basin compared
The Great Basin is the biggest US desert by far and the only one that is properly cold.
What is the Great Basin?
The Great Basin is unusual because no water flows out of it. Every river inside the Great Basin either ends in a lake (like the Great Salt Lake or Walker Lake) or simply disappears into the desert. The region gets its name because it acts like one giant basin that water flows into but never escapes from. The surrounding mountains (the Sierra Nevada to the west, the Rockies to the east) catch and keep the water inside.
The desert sits at high elevation, mostly between 1,200 and 1,800 metres. Long parallel mountain ranges run north-south through the middle, with flat valleys between them. This "Basin and Range" landscape extends across most of Nevada and looks very different from the rolling sand dunes of other famous deserts.
The Great Salt Lake
The largest lake in the Great Basin is the Great Salt Lake in northern Utah. It is the biggest saltwater lake in the western hemisphere, with water 3 to 5 times saltier than the ocean. The lake has no outlet, so water that flows in evaporates and leaves the salt behind. Salt deposits surround the lake and are mined for industrial use.
The Great Salt Lake has been shrinking dramatically since the 1980s due to drought and water diversions for farms and cities. Scientists worry that if the lake dries up completely, toxic dust from its bed could blow across Salt Lake City and cause serious health problems.
The Bonneville Salt Flats
One of the strangest places in the Great Basin is the Bonneville Salt Flats in northwestern Utah. It is a flat plain of pure white salt, approx. 30,000 acres in size, left behind by a giant ancient lake called Lake Bonneville that dried up around 15,000 years ago. The salt flats are so flat and hard that they are used for setting land speed records. The world land speed record (over 1,200 km/h) was set on the Bonneville Salt Flats in 1997.
Wildlife of the Great Basin
The Great Basin's wildlife is hardy. Pronghorn antelope (the second-fastest land animal in the world after the cheetah) roam the open plains. Bighorn sheep live on the rocky mountain slopes. Coyotes, kit foxes and bobcats hunt small mammals. The desert is one of the last strongholds of the greater sage-grouse, a large grouse famous for its elaborate courtship dance.
Deeper dive: Basin and Range geology, Lake Bonneville and the dying Great Salt Lake
The Great Basin sits within a much larger geological feature called the Basin and Range Province, which extends from Mexico through most of Nevada, western Utah and parts of Oregon, Idaho, Arizona and California. The whole region is being slowly stretched east-west as the Earth's crust pulls apart along hundreds of normal faults. This pulling apart causes blocks of crust to drop down (forming basins) while other blocks ride up (forming ranges). The result is the distinctive "washboard" topography of alternating north-south mountain ranges and valleys. The stretching is still happening; the western United States is gradually growing wider.
During the last ice age (which ended around 12,000 years ago), the Great Basin was much wetter than today and contained several enormous lakes. The largest was Lake Bonneville, which covered most of present-day Utah and was approx. 1,000 metres deep at its maximum. Lake Bonneville drained catastrophically around 14,500 years ago when its waters rose high enough to spill over a low pass and carve out the Snake River Canyon as it raced toward the Pacific. The catastrophic flood released around 4,750 cubic km of water in a few weeks, one of the largest floods in geological history. The Great Salt Lake is the small modern remnant of Lake Bonneville.
The Great Salt Lake is now shrinking rapidly. Water diversions for agriculture, growing cities (especially Salt Lake City and its suburbs) and prolonged drought have caused the lake to lose about two thirds of its volume since 1850. The lake reached its lowest recorded level in 2022. As the lake shrinks, more and more of its dry bed is exposed. This bed contains naturally occurring arsenic, lead, mercury and other toxic metals, plus pesticide residues, that can blow as dust into the populated valley. Scientists have warned of a possible "lake dust disaster" affecting millions of people in northern Utah. The state has begun emergency action including buying water rights to send more water back into the lake, but reversing the decline requires fundamental changes in how the region uses water.
The country is the United States. The next biggest US desert is the Chihuahuan.