Illinois Amphibian and Reptile Distributions - Check out what is as well were things are living in Illinois. Great site for biology and environment studies.
INVASIVE PLANT SPECIES IN ILLINOIS FORESTS - IDNR Maps
Illinois County Boundaries 1790 - Present - Click on a year to see the Illinois county map for that year. New counties are listed for each year. To see all of the maps on one page click 'All' but this may take some time to load. Most of the information for these maps came from Origin and Evolution of Illinois Counties published by the Secretary of the State of Illinois.
ILGISA, the Illinois GIS Association, is a not-for-profit association of individuals who use GIS in their work. The purposes of ILGISA are to permit colleagues from around the State of Illinois to gather together to share ideas and concerns and to have an association which can address some of the needs of the membership. Many states have similar organizations because there is cause for colleagues to associate on this topic.
Illinois Natural Resources Geospatial Data Clearinghouse - This site is a gateway to GIS data and imagery for Illinois. Available data sets and documentation (metadata) include: geology, water resources, nature preserves, wildlife areas, land use, political boundaries, roads, census information, Public Land Survey, Digital Raster Graphics files, 1998/99 Digital Orthophoto Quarter Quadrangles, and 2000 Orthoimagery for the Des Plaines River Watershed.
List of Illinois Counties - From Wikipedia, the free encyclopedia Demographic, data, information about the county etc.
Illinois State Geological Survey - Created in 1905, the ISGS provides scientific information to government, business, and the public. Our research and service programs encompass geologic mapping, water and mineral resources, environmental and engineering geology, geochemistry, and education. Explore this site to learn about the many services and programs of the ISGS.Illinois Spatial Data Sets - US Fish & Wildlife Service. The data sets listed are for larger scale data (1:24:000 up to 1:500,000) for the state of Illinois. Data created by or maintained by the U.S. Fish and Wildlife Service is shown in the first table with links to the metadata and data where possible. Data from other agencies is shown in the second table, also with direct links.
Chicago Imagebase - The Chicago Imagebase is a Web-based project aimed at enhancing knowledge about the built environment of the Chicago region. On this site you will find a wide variety of images and other data along with information on how to use this data to study the city.