Windy City Grotto
- Located in Chicago, Illinois and an affiliate of the NSS. Dedicated to exploration, preservation and conservation of the subterranean ecosystem. Contains information about meetings, calendar of events, library holdings and contacts.
- http://windycitygrotto.org/

Rock River Speleological Society
- Formed in 1964 and a Grotto of the NSS. Dedicated to exploration and preservation of karst regions. Includes events, gear, tips, terminology, photos and contact information. Located in Rockford, Illinois.
- http://www.caves.org/grotto/rrss/

Near Normal Grotto
- Located in Bloomington, Illinois and affiliated with the National Speleological Society. Contains information about meetings, membership and contacts.
- http://www.eiu.edu/~physics/nngrotto/nng.htm

Little Egypt Grotto
- Located in Carbondale, Illinois and chapter of National Speleological Society. Dedicated to exploration and conservation. Includes membership information, meeting minutes, Constitution, calendar of events and contacts.
- http://home.globaleyes.net/carbide/

Illinois Speleological Survey, Inc.
- Formed to protect, conserve, locate, record, explore, and study caves and karst resources. Includes Constitution and Bylaws, calendar of events, and contact information.
- http://www.museum.state.il.us/iss/