During the 1990s and early 2000s, agencies including the Illinois State Scientific Surveys (now in the Prairie Research Institute) collaborated to produce comprehensive assessments on major watersheds and ecological regions of Illinois. The results were published in multi-volume sets known as the "Area Assessments," which cover geology, water resources, biota, human impacts, and (in some cases) pre-settlement/early settlement accounts. The Area Assessments are excellent primers on the regions they cover.
In addition to the technical Area Assessments, summaries written for a lay audience were published for most watersheds/regions, with the title "... An Inventory of the Region's Resources."
Documents are listed alphabetically by the watershed/region name. The shaded area in the maps (taken from the report covers) indicate the geographic coverage of each report.
Big Muddy River Area Assessment
Big Rivers Area Assessment
Cache River Area Assessment
Calumet Area Assessment
Chicago River / Lake Shore Area Assessment
Driftless Area Assessment
DuPage River Area Assessment
Embarras River Area Assessment
Fox River Area Assessment
Headwaters Area Assessment
Illinois River Bluffs Area Assessment
Illinois River Bluffs Area Assessment
Kankakee River Area Assessment
Kaskaskia River Area Assessment
Kinkaid Area Assessment
Kishwaukee River Area Assessment
La Moine River Area Assessment
Lower Des Plaines River Area Assessment
Lower Rock River Area Assessment
Lower Sangamon River Area Assessment
Mackinaw River Area Assessment
Mississippi Western Five Area Assessment
Prairie Parklands Area Assessment
Rock River Area Assessment
Shawnee Area Assessment
Sinkhole Plain Area Assessment
Spoon River Area Assessment
Sugar-Pecatonica Area Assessment
Thorn Creek Area Assessment
Upper Des Plaines River Area Assessment
Upper Rock River Area Assessment
Upper Sangamon River Area Assessment
Vermilion River (Illinois River Basin) Area Assessment
Vermilion River Area Assessment
