R. L. Glass 1988 Knowledge of the physical and hydrologic characteristics of geologic materials is useful in determining the availability of groundwater for public and domestic supply and the suitability of areas for on-site septic systems. A generalized map of the Anchorage area shows the approximate distance from land surface to the top of the bedrock surface. Four depth zones are shown. The depths were determined from lithologic data contained in drillers ' logs. (USGS) application/pdf 10.3133/ofr88198 en Map showing depth to bedrock, Anchorage, Alaska reports