Quaternary Geology of Wisconsin — a new statewide map

The 2025 statewide map Quaternary Geology of Wisconsin captures the geologic features formed in Wisconsin during the Quaternary Period, which spans from approximately 2.58 millions years ago to present. The distribution of these sediments is influenced by wind, rivers, lakes, slopes, and the glacial lobes of the North American ice sheet that covered much of the state over several ice ages. This most recent chapter of Wisconsin’s past defines the observable and unique features of the landscape and controls the distribution of silt, sand, and gravel which in turn influence many factors, including nonmetallic mining, groundwater availability, as well as city and road planning.

Created with input from partners across the state, this map incorporates information from high-resolution elevation data as well as detailed county-scale mapping and drilling that has occurred in the last 50 years. As a result, this new publication contains a more accurate and comprehensive set of sedimentary units and landforms that will be used by decision makers as well as educators and outdoor enthusiasts interested in the Wisconsin landscape.

This map is available for free to download at its intended size (poster) for printing as well as a digital format to use with mobile apps. More information below!