Bedrock Geology of Portage County, Wisconsin Bedrock Geology Frac Sand Data and Resources ZIP IC53-DI Bedrock Geology of Portage County, Wisconsin [GIS data] Greenberg, J.K.; Brown, B.A.; 1986 GIS Data: Shapefiles, MrSID Download IC53-plate01 Bedrock Geology of Portage County, Wisconsin [plate 1] Greenberg, J.K.; Brown, B.A.; 1986 Map: Scale 1:100,000 Download Related Collections Information Circular View Information Circular