Among the pioneers of ecological research in the arid zones of Lara are Henri Pittier and Francisco Tamayo (Smith and River, 1983). Since the 1940s, both researchers have warned of the dangers posed by the unsustainable exploitation of natural resources in the arid zone. Pittier suggested, in 1948, that the impact of goat herding could be irreversible, impeding the natural regeneration of the degraded communities. For his part, Tamayo described in 1962, the changes that overgrazing caused in the vegetation, favoring the dominance of unpalatable toxic or thorny species.

Despite their efforts, there were no integrated conservation or ecology programs for the semiarid region of Venezuela during the 1970s, partly because Loma El León covers a smaller surface area than most of the other national protected areas. To address this precarious situation, Smith, Rivero, Garcia, and Salazar conducted a series of studies on ecology and human influence in the arid zones of Lara State. Their study served as a basis for the declaration of the natural monument in 1990 (Smith and Rivero, 1983; García et al., 1990; García and Salazar, not dated). Their studies included the compilation of existing information on the ecology of arid ecosystems in the zone between Barquisimeto and Carora, a description of the natural physical aspects of the vegetation (including maps and a preliminary list of the flora of Loma El León), and an analysis of the effect of goats grazing on the vegetation and soil. The work of Smith and Rivero (1983) includes a preliminary list of mammals, amphibians, and reptiles of the arid zone of Lara, as well as of the birds in the arid zones of Lara and Falcón. Similarly, Wingfield completed a preliminary list of flora for Falcón State in 1975 (Huber et al., 1998). Even without a published catalog of flora for the