The upper Verde River area includes about 3,600 square miles in north-central Arizona. The area is underlain by a regional aquifer that consists of several formations. In places ground water also is present in the igneous rocks and basalt flows and in the alluvium along the channels and flood plains of the streams. Ground-water development has been slight; in 1978 about 8,000 acre-feet of ground water was withdrawn for domestic, public-supply, industrial, and irrigation uses. Information on the maps includes the principal geologic formation that furnishes water to wells and springs, depth to water, altitude of the water level, and chemical quality of the water. Scale 1:125,000. (USGS)