This report describes the different, and sometimes conflicting, conceptions of land use that have been held by residents of southern Arizona during the past 500 years. Briefly outlining major events in the Native American, Hispanic, and Anglo experience, the report provides a chronology of events.

Describes a number of streams within watershed planning units and prioritizing these streams according to their existing contribution to the overall conservation of biological diversity in Pima County. Over 50 percent of the priority streams within the County are found within the Altar Valley and the Cienega Rincon area.