The Mariposa Monarca Biosphere Reserve is located mostly in the eastern part of the state of Michoacán with some being in the western part of the State of Mexico in the central Mexican highlands. The Reserve was created to protect the wintering habitat of the monarch butterfly and contains over 56,000 hectares of land.
As of the winter of 2007-2008, there were twelve major colonies or sanctuaries of monarch butterflies covering a total of 4.72 hectares of land wintering in Mexico, same as the winter before and up from the seven that existed in winter 2004-2005. Eight of these twelve are within the Biosphere. Four of these eight are open to the public. These are:
* Sierra Chincua - near the towns of Tlalpujahua and Angangueo in Michoacán.
Latitude: N. 19° 39' 39.53" Longitude: W. 100° 16' 4.66" Elevation: about 10,300 feet.
* El Rosario - near Ocampo in Michoacán.
Latitude: N. 19° 35' 16" Longitude: W. 100° 16' 4"
* La Mesa - near San José del Rincón in the State of Mexico
* El Capulín - near Donato Guerra and San Juan Soconusco in the State of Mexico
Other sanctuaries such as those near San José Villa de Allende and Ixtapan del Oro are not actively promoted for tourism because of the risk of harm to these butterfly colonies.
While the Biosphere still has problems with infrastructure, most notably with trash especially around parking and merchant areas, a number of improvements have been recently made, most notably in the sanctuary of El Rosario. These include well-defined footpaths with security patrols and stone/or concrete steps in steep places to help against erosion. Horsepaths were also eliminated for erosion reasons.
During winter 2008-2009, there are plans to tag as many of the wintering butterflies as possible using very light self-stick tracers as to not impede their flight. The purpose of this is to determine the butterflies exact migration route as they fly back north to the U.S. and Canada in the spring.
Source: http://en.wikipedia.org/wiki/Monarch_Butterfly_Biosphere_Reserve
