LOCALIZATION: In the northwest of Pitiquito Municipality, 70 km from Caborca and 40 km east of Puerto Libertad.

AREA: 10,375 hectares, mainly of hills, flatlands and mountain areas, from 300 to 1030 meters above sea level, including part of the Sierra “El Viejo”.

CLIMATE: Desertic, very dry and semi-hot, with a biannual rain cycle, with rains in summer and occasionally in fall or winter.

VEGETACION: Desertic microphyle bush in the flatlands, with such species as creosote bush (Larrea tridentate), jojoba (Simmondsia chinensis), sahuaro (Carnegiea gigantea) and iron wood (Olneya tesota). In the mountainous ranges, sarcocaule microphyle bush predominates, with elephant tree (Bursera microphylla) and sangregado (Jatropha cardiofila).

BIODIVERSITY OF EL PLOMITO, SONORA.

Group	No. of species	Endemics	Special protection	Threatened	Rares
Plants	74		1		1
Amphibians	3
Reptiles	26	1	3	6	1
Birds	64		1	3
Mammals	19		1

ECOLOGICAL BENEFITS: The Sierra “El Viejo” is considered among the high priority conservation areas by the Mexican Federal government, and hold the biggest number of desert bighorn sheep (Ovis canadensis mexicana) in Sonora (continental). Also, there are other species with economic, cultural and ecological importance, such as the mule deer (Odocoileus hemionus eremica) and white-tailed deer (Odocoileus virginianus couesi).

Among the reptiles, there is an endemic species called the Chuckwalla (Sauromalus obesus), and one of the only two venomous lizards in the world, the Gila Monster (Heloderma suspectum), in Mexico being found only in Sonora.