Alexander, E. C., Jr.Alexander, Scott C. (Geologist)Boerboom, Terrence J.Shade, Beverley L.Map showing the thickness (depth to bedrock) of unconsolidated sediments (Quaternary glacial and stream materials) over the bedrock surface and elevation of the bedrock surface (bedrock topography), scale 1:200,000; map showing locations of sinkholes and sinkhole cross sections, scale 1:100,000, Pine County.PDFengMinnesota Geological SurveyPublicGeologic atlas of Pine County, Minnesota, C-13, Part A, Plate 6, Sinkhole distribution, Depth to Bedrock, and Bedrock TopographyMapsMinnesota2001University of Minnesota