Map showing ground-water conditions in the Tonto basin area, Gila County, Arizona; 1978-79

The Tonto basin area includes about 955 mi² in central Arizona. The area is bounded on the north by the Mogollon Rim, on the east by the Sierra Ancha Mountains, on the west by the Mazatzal Mountains, and on the south by Theodore Roosevelt Lake. The area is drained by Tonto Creek, which flows north to south and discharges into Theodore Roosevelt Lake. 

Because the Tonta basin area is entirely within the Tonto National Forest, only about 3 percent of the land is privately owned and, for the most part, wells inventoried were on private land. Only selected wells are shown on the map because of the high well density on the private land.