[1] The protected area consists of many isolated blocks of land, mostly atop the north–south mountain ridges of the southern Sierra Madre Occidental.

The easternmost range is the Sierra Fría, between the Juchipila and Verde rivers, where it adjoins the Cuenca Alimentadora del Distrito Nacional de Riego 01 Pabellón.

It also includes portions of the westernmost Trans-Mexican Volcanic Belt, to the south between the Río Grande de Santiago and Ameca rivers.

The natural vegetation is pine–oak forest and woodland, with pines and/or oaks as the dominant trees, together with manzanillo (Arbutus spp.

glauca, Taxodium huegelii[3] Guajolote, pavo salvaje (Meleagris gallopavo), Venado cola blanca (Odocoileus virginianus ), Pecari de collar (Pecari tajacu), Venado cola blanca (Odocoileus virginianus ), Puma (Puma concolor), Coyote (Canis latrans), Conejo castellano o serrano (Sylvilagus floridanus), Liebre cola negra (Lepus californicus), águila real (Aquila chrysaetos), Codorníz de moctezuma (Cyrtonyx montezumae), Chichimoco (Tamias bulleri), Búho moteado (Strix occidentalis), Serpiente de cascabel (Crotalus lepidus), Trogón orejón (Euptilotis neoxenus), Guacamaya verde (Ara militaris), Pato friso (Anas strepera), Cerceta ala azul, pato media luna (Anas discors), Pato cucharón norteño (Anas clypeata), Codorniz cotuí (Colinus virginianus), Paloma ala blanca (Zenaida asiatica), Paloma huilota (Zenaida macroura), Tórtola Cola Larga (Columbina inca), Tórtola Coquita (Columbina passerina), Topote del pacífico (Poecilia butleri), Murciélago negruzco, murcielaguito oscuro (Myotis nigricans), Jaguarundi, leoncillo (Puma yagouaroundi), Nutria de río (Lontra longicaudis), Jaguar (Panthera onca), Ocelote, tigrillo (Leopardus pardalis), Culebra nocturna ojo de gato (Hypsiglena torquata), Culebra ciempiés del Pacífico (Tantilla calamarina), Culebra real coralillo (Lampropeltis triangulum), Iguana negra (Ctenosaura pectinata)[3] The area was designated a protected forest area and watershed in August 1949.