About
While the southwestern United States and northern Mexico are known for being arid, perhaps no place appears more lifeless and stereotypically desert-like than the Gran Desierto de Altar in northwestern Sonora. Although Death Valley is actually drier, this desert is uniquely the only active erg (desert sand dunes) in North America, making in particularly inhospitable for life. The dunes, which are in some places over 12 kilometers thick and 10 meters high, were deposited by the Colorado River 120,000 years ago when it flowed further east through the area.
A surprising amount of life does thrive in the dunes, however. Shrubs grow in areas of thinner sand, and the desert has in fact long been a refuge for flora during colder periods of prehistory. There are also numerous species of rodents, reptiles, and over 200 species of birds in the area. To the east lies El Pinacate, a contrastingly dark-soiled area of extinct volcanoes and lava flows.
Know Before You Go
Visiting Gran Desierto de Altar requires checking in and paying a fee at the Schuk Toak Visitor Center. There are 80 kilometers of dirt road accessible by high-clearance vehicle. The desert is in the "hassle-free zone" in which a vehicle import permit is not required if driving from the United States.
