This report is one of several from Statistical Research Inc. written to develop the Cultural and Historic Resources Element of the Sonoran Desert Conservation Plan. Divided into four parts, the report summarizes available information that reflects the experience of (1) ancient peoples of Southern Arizona; (2) indigenous peoples; (3) non-indigenous peoples of the historical period; and (4) Pima County today.

The depiction of a historical-period property on an early map, whether a house, a ranch, a mining prospect, or an irrigation canal, is often the earliest (and sometimes the only) evidence that cultural features once existed in a particular place. Statistical Research used early maps as a regional preservation-planning tool by systematically examining a group of early maps of the county for depictions of cultural features. The typology will be used to plot the sites, distinguished by type, on a single map (or possibly on a series of maps) to be digitized by Pima County and incorporated into its GIS database.