Geologic Map of the Sawtooth Mountains and the North End of the West Silver Bell Mountains, Pinal and Pima Counties, Southern Arizona v.2.0

The Sawtooth Mountains are a small (45 km2 ), low-relief (250 m), yet rugged range composed of essentially flat-lying, Mid-Tertiary volcanic rocks. Along with the West Silver Bell Mountains, which consist mostly of Middle Proterozoic granitic rocks, the ranges form the southwestern boundary of the Picacho basin, a major north-trending, approximately 20 km-wide, 3 km-deep basin in the Basin and Range structural province of southern Arizona. Access on paved roads is possible from Interstate 10, taking Sunland Gin Road about 20 km south to within few kilometers of the Sawtooth Mountains. From this point, four-wheel drive vehicles are required to negotiate the crossings of sandy washes on all roads that lead into the mountains. The east slope of the range is steep and rugged, but the west side is very gentle, with older Quaternary fan surfaces extending to within a kilometer of the ridge crest in some areas. Road access within the range is fairly extensive, but the main east-west road through the middle includes a very steep climb on the east slope that is impassable to practically all conventional fourwheel drive vehicles.