 The Biosphere reserve was established by a Mexican presidential decree of 6 June 1994, which designated a core area and buffer zones.The core area is centered on the higher-elevation oak-pine forests, while the transition area includes the communities of Todos Santos, El Pescadero, El Triunfo, San Antonio, San Bartolo, Buena Vista, Los Barriles, Las Cuevas, Santiago and Miraflores.The climate is influenced by its altitude.