Chihuahuan Desert
The Chihuahuan Desert is the largest desert in North America. It covers parts of northern Mexico and three US states (Texas, New Mexico and Arizona). Unlike the famous low-lying hot deserts of the Sahara or Arabia, the Chihuahuan is a high-elevation desert; most of it sits above 1,000 metres. It is bordered by huge mountain ranges and is surprisingly green in parts, with grasslands and yucca plants more than rolling sand.
- Areaapprox. 450,000 km²Largest desert in North America
- CountriesMexico and USAMostly in Mexico
- Elevation1,000 to 1,800 mHigh-elevation desert
- Rainfallapprox. 230 mm/yearMost in summer monsoon
- Iconic plantLechuguilla agaveMarks the desert's boundaries
- Famous parkBig BendIn Texas, along the Rio Grande
North American deserts compared
The Chihuahuan is the second largest US-area desert. Much more of it lies in Mexico than in the US.
What is the Chihuahuan?
The Chihuahuan Desert sits in the high country between two major mountain ranges: the Sierra Madre Occidental to the west and the Sierra Madre Oriental to the east. Moist air from the Pacific and the Gulf of Mexico is wrung out by these mountains, leaving the central plateau dry. The Chihuahuan extends north from the Mexican state of Zacatecas into Chihuahua state (after which it is named), then across the Rio Grande into the southwestern United States.
A "cool" desert
Because of its high elevation, the Chihuahuan is significantly cooler than the lower Sonoran and Mojave deserts. Winter nights regularly drop below freezing, and snow falls in the higher parts. Summer days are hot but not as extreme as in Death Valley. The combination of higher rain and cooler temperatures means the Chihuahuan supports more desert grasslands than other North American deserts. Many ranchers run cattle in parts of the Chihuahuan that look more like savanna than desert.
Wildlife of the Chihuahuan
The Chihuahuan is home to surprising biodiversity, including unique plants and animals adapted to high cool desert. The kangaroo rat can live its entire life without ever drinking water, getting all the moisture it needs from seeds. The desert's endangered Mexican grey wolf is slowly recovering after near-extinction. Black bears live in the mountain "sky islands" rising from the desert. Pronghorn antelope roam the grasslands. The desert is also a critical migration corridor for hundreds of bird species.
Big Bend
Big Bend National Park in Texas is the most-visited part of the Chihuahuan. The park covers around 3,200 square km along the Rio Grande, named for a giant bend the river makes through the desert mountains. Big Bend has spectacular canyons (Santa Elena, Mariscal, Boquillas), mountain peaks (the Chisos Mountains rise to over 2,300 metres inside the park), and the most dark sky in the lower 48 US states for stargazing.
Deeper dive: high-elevation deserts, the Sky Islands and the borderlands
The Chihuahuan is a classic high-elevation desert. Most of the surface lies between 1,000 and 1,800 metres above sea level, which dramatically affects the climate. Air temperature drops roughly 6.5 °C for every kilometre of elevation gain, so the Chihuahuan is naturally cooler than a comparable lower-altitude desert. The thinner air at altitude also has less greenhouse effect, so nights cool down faster: temperature swings between day and night can exceed 25 °C. The combination of cool winters and brief but real summer rains supports a richer plant community than hotter deserts elsewhere.
Within the Chihuahuan rise several isolated mountain ranges known as Sky Islands. The Chisos Mountains in Big Bend, the Davis Mountains in west Texas, the Sierra Madre Occidental in Mexico and others rise high enough to support pine and oak forests on their upper slopes. These forests are isolated from each other by miles of intervening desert. The Sky Islands are biological islands too, each supporting populations of animals and plants that have been separated from their relatives for tens of thousands of years. They are among the most biodiverse areas in North America and contain many endemic species (organisms found nowhere else).
The Chihuahuan Desert lies along the US-Mexico border for over 1,000 km. The desert's harsh terrain has been a major obstacle to migration in both directions throughout human history. The construction of the modern border wall along sections of the desert has had significant ecological impacts, blocking wildlife migration corridors that connect protected areas in Mexico (such as Maderas del Carmen) with US national parks (such as Big Bend). Jaguars, ocelots, Mexican grey wolves, bighorn sheep and many bird species all depend on being able to move across the border. Both governments and conservation groups have worked on cross-border partnerships, but political tensions have made this difficult.
The countries are Mexico and the United States. The other big North American desert is the Sonoran Desert.