and recurrent zoonoses, vector-borne and non-vector-borne, such as for arenaviruses. The important point is that, although particular zoonotic diseases have particular etiologic agents, the controlling conditions for each may have enough similarities to provide us with predictors of risk for acquisition and, therefore, with bases for prevention and control measures.

The authors thank the numerous people, not mentioned specifically, who assisted us in the field, helped with logistics, advised, consented, and otherwise made this work possible. In particular we thank K. M. Canestorp, U.S. Fish and Wildlife Service, Colorado Fish and Wildlife Assistance Office, Lakewood, Colorado, who provided background information about the PCMS and anticipated rodent habitats; Dan Sharp, U.S. Fish and Wildlife Service, Colorado Fish and Wildlife Assistance Office, Lakewood, Colorado, for his persistence in surveying the flora; and employees of the Directorate of Environmental Compliance and Management, Ft. Carson, for allowing us to use the Pinon Canyon Maneuver Site to conduct these studies. We are extremely grateful to N. Doeskin, Department of Atmospheric Sciences, Colorado State University, Fort Collins, and J. Kuzmiak, U.S. Geological Survey, Pueblo, Colorado, who generously provided climatologic data. T. Ksiazek and others at the U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, provided enthusiastic support and reagents with which to do the serologic tests. Funding for this work was provided by the U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, under cooperative agreement No. U50/ccu809862-03, for which we are grateful. Ms. Brooke Roeper, Colorado State University, provided the templates from which we devised Figures 2-24 and 2-25.

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