El Pinacate y Gran Desierto de Altar Biosphere Reserve (Spanish: Reserva de la Biosfera El Pinacate y Gran Desierto de Altar), is a biosphere reserve and UNESCO World Heritage Site managed by the Federal government of Mexico, specifically by Secretariat of the Environment and Natural Resources, in collaboration with state government of Sonora and the Tohono O’odham.
It is in the Sonoran Desert in Northwest Mexico, east of Gulf of California, in the eastern part Gran Desierto de Altar, just below the border of Arizona, United States and north of the city of Puerto Peñasco. It is one of the most significant visible landforms in North America seen from space. A volcanic system, known as Santa Clara is the main part of the landscape, including three peaks; Pinacate, Carnegie and Medio.
In the area there are over 540 species of plants, 40 species of mammals, 200 of birds, 40 of reptiles, also amphibians and freshwater fishes. There are threatened endemic species as sonoran pronghorn, bighorn sheep, gila monster and desert tortoise.
The extension of the Biosphere Reserve is 7,146 km², greater than that of the states of Aguascalientes, Colima, Morelos and Tlaxcala separated.