County Geologic Atlas Program


The County Geologic Atlas program exists to develop maps and reports of the geology and hydrogeology of Minnesota. It is currently a joint program, with more recent atlases produced in two parts.

  • Part A - Geology is developed by the Minnesota Geological Survey (MGS).
  • Part B - Hydrogeology is developed by the DNR, expanding on the information from Part A. 

Mapped Areas

This website primarily outlines the DNR products and information for part B. Documents include maps and reports of geology, groundwater, pollution sensitivity, and some special studies (e.g., the distribution of sand and gravel deposits, sinkholes, or other features of interest).

Most projects provide chemistry data and GIS files of the geology and groundwater maps. Documents may be produced by county, region, state, or by special project request. See Maps and Studies for details.


These documents are used by governments in long-range planning efforts to protect and preserve groundwater, provide information for permitting, for source water protection and well sealing programs, for short-term emergency response to contaminant releases, and by businesses and citizens.

Training on atlas use can be provided upon request. Contact the program supervisor (Contacts).

The Geologic Atlas User's Guide provides a framework of the subsurface environment that provides our water the resources,  describing the materials and features beneath the surface from soil to bedrock and beyond. The purpose is to explain where our water comes from, how geology and climate control its distribution, and how we can maximize the availability of high quality water for ourselves and the habitat we live in.


Program funding comes from the DNR Ecological and Water Resources budget as appropriated by the legislature. Projects may also be supplemented by other funding sources that support geologic mapping at the MGS.

New atlas projects have been supported at the MGS since 2007 and the DNR since 2009 by additional funding from the Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources. Beginning in 2010, county geologic atlases have been supported by additional funding from the Clean Water Fund.

For a county atlas project, the state contributes from 80% to 85% of the project's total cost. The county is required to participate in the project, typically by establishing accurate locations for wells with construction records. No cash contribution is required of the county.

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