SHUK TOAK. HISTORIA NATURAL Y CULTURAL DE UN GEOSÍMBOLO DE SONORA.

In the northwestern corner of Sonora, México, there exists an arid region covered by a volcanic shield that is close to both a singular sea of sand dunes and the Sea of Cortez. Temperature in this place may reach 56.7°C in the summer and -8.3°C during winter. In addition, with only 52 millime- ters of annual rain, one could assume that this is an uninhabited landscape. However, the Desert of Altar and the volcanic shield of El Pinacate has characterized since the Pleistocene Era because of the existence of a singular biodiversity of which many specimens of fauna and flora transcend the current times. For these characteristics of this area, the Mexican government declared it, in 1993, a protected natural area with the name of Biosphere Reserve El Pinacate and the Great Desert of Altar. Moreover, this region has been historically relevant not only because of its physiographic and environmental singularities, but also because of the long presence of man. This place was inhabited by human beings since the Paleoindian and the Late Prehistoric periods, and has repeatedly been explored since the 17th Century to present by missioners, colonizers, gold seekers, hunters, and on the top of all scientists. Among the most important visitors to this land should be mentioned Fray Eusebio Francisco Kino, Carl Lumholtz, William Hornaday and Julian Hayden. This paper presents these two histories, the natural and the cultural, and discusses geological, morphological and physiographic aspects of this reserve, as well as those about biodiversity, early presence of man and ulterior explorations. This paper is the result of a wider project financed by the National Commission for the Protected Natural Areas (CONANP). The purpose of this research was to elaborate a museum exhibition in the Visitors Center of that place. [ABSTRACT FROM AUTHOR]