The "Springerville area," Apache County, Arizona (Fig.l) initially was selected as a site-specific target for geothermal exploration on the basis of (1) moderate to high chemical geothermometers, (2) the proximity of young volcanics, and (3) the intersection of regional lineaments that were defined by the alignment of young volcanics in the White Mountain volcanic field (Hahman, pers. commun., 1977). Based on prior work by Swanberg and others (1977), the initial program focused on the area between the towns of Springerville and St. Johns. Later work directed exploration farther south between the towns of Springerville and Alpine, and to the west thereof. Sufficient data were generated to indicate a potential geothermal resource and thus to encourage the Bureau of Reclamation to fund specific geophysical surveys (passive seismic, d.c. resistivity, telluric current, and heat-flow drilling) that supplemented investigations being funded by the Department of Energy, Division of Geothermal Energy. p.23