Remote sensing, geophysics, and geochemistry were used in a cooperative program between the U. S. Geological Survey and the Consejo de Recursos Minerales of Mexico to develop exploration techniques for porphyry copper deposits in northern Sonora, Mexico. By the use of a multidisciplinary team approach, at least four northeast-trending lineament zones have been defined. These zones are interpreted to be premineral structurally defined zones that are a primary regional control of mineralization in the porphyry copper province of northern Sonora. Northwest-trending structures are also an aspect of the control of mineralization; however, our data indicates that the northwest-trending structures are pervasive, and therefore are not a useful regional prospecting guide. The northeast lineament zones postulated here are systematic and localized and therefore can be used as regional prospecting guides.The northeast-trending lineament zones are defined by concentrations of linear features oriented northeasterly, areas of limonite concentrations on the flanks of the lineament zones, subtle deflections on the regional gravity field aligned on northeast trends, anomalous geochemical trends oriented northeast, and the presence of known porphyry copper deposits along the lineament zones. From south to north the lineament zones are named the Cumpas, Bacoachi, Cananea, and Nogales lineament zones.On the basis of all the data, the Nogales lineament zone appears the most promising for the location of an economic mineral deposit. From the regional reconnaissance data at least three distinct hydrothermal systems are indicated along the Nogales lineament zone. The farthest southwest of these three systems is approximately 60 km from Nogales, north and northeast of San Juan; the second is about 50 km southwest of Nogales, south-southwest of El Correo; and the third is just southwest of Nogales.