If you think another organisation/program should be listed, comment on this post or e-mail me at firstname.lastname@example.org, and I'll add it!
Cook CountyAcorns to Oaks
Park District of Oak Park, with opportunities at Oak Park Conservatory
Chicago Botanic Garden
Chicago Park District
Including Lincoln Park Conservatory
Garfield Park Conservatory
Forest Preserves of Cook County
Plants of Concern
A Chicago Botanic Garden program utilising citizen science for rare-plant monitoring; stewardship opportunities!
Student Conservation Association - Midwest
Lake CountyConserve Lake County
Lake County Forest Preserves
Liveable Lake County/Sierra Club Woods & Wetlands
Kenosha County (Wisconsin)Chiwaukee Prairie
Garden of Eatin'
Root-Pike Watershed Initiative Program
Statewide/Etc.Forest Preserve District of DuPage County
Including Kline Creek Farm
Forest Preserve District of Will County
Illinois Department of Natural Resources
The Nature Conservancy
several opportunities including Volo Bog & IL Beach State Park