Meyer, Gary N.Mossler, John H.Swanson, LynnMap showing the elevation of the bedrock surface (bedrock topography) and the confining units (non-aquifer rock layers that prevent movement of ground water vertically) within the St. Peter Sandstone, scale 1:48,000.PDFengMinnesota Geological SurveyPublicGeologic atlas of Ramsey County, Minnesota, C-7, Plate 4, Bedrock TopographyMapsMinnesota1992University of Minnesota