_]f T_ UEPAC is located in north central Sonora on the Sonora River (Figure 1). Hermosillo, the capital of the state, lies to the southwest; Cananea, a copper-mining town, to the north; and Nacozari, another copper center, to the northeast. All three are approximately one hundred miles by road f rom Huepac. Hermosillo is a stop on the Sud-Pacifico de Mexico, and Cananea and Nacozari are railhead towns. Huepac is on no railway and has only the road, the old camino real. By the site of Huepac passed explorer, conqueror, and missionary. Huepac, itself, was a Jesuit mission foundation. Now the occasional passage of an automobile gives only limited contact with the outside world, and Huepac remains a rather remote agricultural village, depending chiefly upon its own fields and grazing lands.