ACRES, Inc.
- Protects 40 nature preserves in 11 Northeast Indiana counties.
- http://acreslandtrust.org

Indiana Sassafras Audubon Society
- Serving the Indiana counties of Monroe, Lawrence, Greene, Morgan, Brown and Bartholomew.
- http://www.bloomington.in.us/~audubon/

Sycamore Audubon Society
- Membership consists of members living in Benton, Carroll, Clinton, Tippecanoe, Warren, and White counties, with the purpose of defending our natural environment.
- http://www.sycamoreaudubon.org/

Indiana Lakes Management Society
- Purpose is to promote and encourage the understanding and comprehensive management of lakes and reservoirs and their watershed eco-systems.
- http://www.indianalakes.org/

COPA, Inc.
- Dedicated to presenting information concerning the PCB problem in south central indiana.
- http://copa.org/

Hoosier Environmental Council
- The only environmental group providing in-depth research and advocacy on the broad range of Indiana, national and international environmental issues.
- http://www.hecweb.org

Indiana Audubon Society
- An independent, Indiana oriented, statewide organization.
- http://www.indianaaudubon.org/

Indiana Native Plant and Wildflower Society
- Promoting the appreciation, conservation, beauty, diversity and environmental importance of indigenous vegetation.
- http://www.inpaws.org/

Sycamore Land Trust
- South-central Indiana non-profit organization whose mission is the preservation of the disappearing landscape.
- http://www.bloomington.in.us/~sycamore/

Indiana Conservation Officers Organization, Inc.
- A not for profit representing active and retired officers and associate members on legislative issues and educational issues that support IDNR's goals in enhancing our life sports.
- http://www.icoo.com/

Indiana Karst Conservancy
- Protecting caves through active conservation.
- http://www.caves.org/conservancy/ikc/

Citizens Action Coalition of Indiana
- A not-for-profit coalition of organizations and over 300,000 individual members throughout the state of Indiana. For over two decades CAC has worked to empower citizens, promote economic and environmental justice.
- http://www.citact.org/

Central Indiana Land Trust Incorporated
- A nonprofit corporation acting to protect natural spaces in the face of increasing urban sprawl.
- http://www.cilti.org/

Soarin' Hawk Raptor Rehabilitation
- Providing quality care to injured hawks, owls, eagles and falcons in Northeast Indiana.
- http://www.soarinhawk.org/

Save the Dunes Council, Inc.
- Dedicated to preservation and protection of the Indiana dunes.
- http://www.savedunes.org/