Stephen J. Char Gary E. Baumbach Diana L. Dugas 1995 This report describes basic data used to develop Geographic Information System data sets of bedrock geology, sinkholes and closed depressions, and spring and well locations attributed with hydro- geologic and water-quality data in the Pequea and Mill Creek watersheds, a 210-square-mile area in Lancaster and Chester Counties, Pa. The data sets, which do not contain hydrogeologic interpretations, were developed by the use of ARC/INFO software during 1990-93 by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Environmental Resources. The U.S. Environmental Protection Agency proposes to use these noninter- pretive and interpretive data sets, and those from other sources, to aid in the assessment of ground- water vulnerability to pesticides in the Pequea and Mill Creek watersheds. application/pdf 10.3133/ofr95113 en U.S. Geological Survey Geographic information system data sets of hydrogeologic conditions in Pequea and Mill Creek watersheds, Pennsylvania: Part I — Basic data reports