Gran Desierto de Altar

Gran Desierto de Altar is a vast desert in northwestern Sonora, Mexico, extending into southwestern Arizona and forming the largest continuous wilderness in the Sonoran Desert. It is distinguished by North America’s only active erg, a sand sea of broad sand sheets, dune fields, and towering star dunes. Along its eastern edge, the dunes meet the volcanic Sierra Pinacate, together forming the El Pinacate y Gran Desierto de Altar Biosphere Reserve and a UNESCO World Heritage Site. Shaped by Colorado River sediments, shifting faulting, and ongoing tectonic activity, this harsh but resilient landscape also supports characteristic lower Sonoran Desert plants and animals.

Sonora · Mexico