Data

Gamma-Ray Logs Database screenshot
The ISGS Geologic Mapping Program Gamma-Ray Logs Database uses an interactive map to allow users to view individual logs and standardized borehole location information for 19 counties in Illinois. [...]
The Coal Mines in Illinois Viewer illustrates a general depiction of underground mining in the state and will help determine the proximity of coal mines and underground industrial mines to your home or business. [...]
Illinois Geospatial Data Clearinghouse logo
The Illinois Geospatial Data Clearinghouse is an established node of the National Spatial Data Infrastructure Clearinghouse Network. [...]
Illinois Historical Aerial Photo Cook County
On May 12, 1933, President Franklin Roosevelt signed into law the Agricultural Adjustment Act, which was originally administered by the United States Department of Agriculture, Agricultural Adjustment Administration (USDA-AAA). Since the mid-1930s, the USDA-AAA, now the USDA Farm Services Agency, periodically acquired nationwide aerial photographs by county. These aerial photographs were originally used by the USDA-AAA to assess the nation's agricultural lands and served as the basis for the national soil surveys. [...]
Public Land Survey System (PLSS)
Instructions: This web page will allow you to enter an Illinois address and determine its legal description to the section level-of-detail. [...]