The Concho, St. Johns, and White Mountains areas cover about 2 ,300 sq mi in eastern Arizona. Ground water is present in several aquifers that are made up of one or more formations. The maps show ground-water conditions in the Coconini aquifer; in the Triassic, Cretaceous, and Tertiary rocks; and in the alluvium and basaltic rocks. Information on the maps includes depth to water, altitude of the water level, chemical quality of the water, irrigated area, and hydrographs of the water level in selected wells. Scale 1:125,000. (Woodard-USGS).