Author & Contributor Index
- Illinois. Natural History Survey Division. LTRMP Havana Field Station
- Illinois. Natural History Survey Division. River Research Laboratory
- Illinois Nature Preserves Commission
- Illinois. Office of Capital Development/Engineering
- Illinois. Office of Solid Waste and Renewable Resources
- Illinois Office of Water Resources
- Illinois River Strategy Team
- Illinois Secondary School Principals' Association. Curriculum Committee. Junior-College Committee
- Illinois. Section of Faunistic Surveys and Insect Identification
- Illinois. Section of Wildlife Research
- Illinois Specialty Growers Association
- Illinois State Academy of Science
- Illinois State Archaeological Survey
- Illinois State Department of Public Health
- Illinois State Department of Public Health and the University of Illinois
- Illinois State Department of Public Health Division of Sanitary Engineering and the University of Illinois Department of Civil Engineering
- Illinois State Entomologist,
- Illinois. State Entomologist
- Illinois State Geological Survey
- Illinois State Geological Survey Coal Section
- Illinois State Geological Survey. Hydrogeology and Geophysics Section
- Illinois State Geological Survey. Wetlands Geology Section
- Illinois State Horticultural Society
- Illinois State Laboratory of Natural History
- Illinois State Library, Illinois Heritage Association
- Illinois State Museum
- Illinois State Natural History Survey
- ILLINOIS STATE NATURAL HISTORY SURVEY
- Illinois State Toll Highway Authority
- Illinois State University
- Illinois State University. Department of Geography-Geology
- Illinois State Water Survey
- Illinois State Water Survey,
- Illinois State Water Survey Center for Watershed Science
- Illinois State Water Survey. Chemistry and Hydrology Divisions
- Illinois State Water Survey Division
- Illinois State Water Survey, Hydrology Division
- Illinois State Water Survey. Office of Sediment and Wetland Studies
- Illinois State Water Survey Surface Water Hydrology and Hydraulics Section
- Illinois State Water Survey, Water Quality Section
- Illinois State Water Survey. Watershed Science Section.
- Illinois Sustainable Technology Center
- Illinois Terrorism Task Force
- Illinois. The Division of Highways
- Illinois Transportation Archaeological Research Program
- Illinois. University. Department of Household Science
- Illinois. University. Engineering Experiment Station
- Illinois. University. Extension Service in Agriculture and Home Economics
- Illinois Waste Management and Research Center
- Illinois. Waste Management and Research Center