Hydrologic data collected on the Great and Denbow Heaths, Maine, include precipitation, pan evaporation, air temperatures, streamflow, and ground water levels. These data were collected for a peat bog hydrology study conducted in cooperation with the Maine Geological Survey. The data network consisted of climate information from three rain gages, an evaporation pan and two maximum-minimum thermometers; surface water information from two continuous gaging stations and 19 partial record sites; groundwater information from an observation well equipped with a continuous recorder and 106 piezometers. Methods used for the collection and analyses of data included standard Survey techniques modified for the unique hydrologic environment of the study area. (Author 's abstract)