Illinois Department of Natural Resources

October 2014 Updates:

List of Endangered & Threatened Species in IL by County

List of Illinois Natural Areas Inventory (INAI) Sites by County

List of Illinois Nature Preserves Commission (INPC) Protected Lands by County

Please Note: The IL Natural Heritage Database is updated daily with data pertaining to threatened and endangered species occurrences in IL. Please check this website quarterly for updates to this list or contact staff directly at or call 217-782-2685.

A comprehensive source of information on the state's endangered and threatened plants and animals, exceptional natural communities and special geological features.

Beginning in 1986, the Illinois Department of Natural Resources' Division of Natural Heritage, in conjunction with The Nature Conservancy, established the Illinois Natural Heritage Database to be a central location of information on significant natural features within the state. The database contains the information gathered during the Illinois Natural Areas Inventory conducted in 1976-1978 as well as recent information. Resource planners can save time and money by referring to the database for comprehensive natural heritage data.


The database has compiled information from a broad range of sources, including museum and herbarium collection records, publications, and experts throughout the state. Guided by this information, the Division of Habitat Resources participates in considerable field surveys every year to build the database and keep it current. Staff members, contractors and volunteers perform field surveys to find and verify specific locations of the features of highest priority and to collect accurate information on the condition, quality and management needs of these features. This process of compiling and verifying data is ongoing, thus continuously updating and improving the database. Information is easily accessible in manual, map and computer files that are cross-referenced to provide a flexible data management system. Data can be retrieved from these files in a variety of formats tailored to the needs of different users.

How Can the Database Be Used?

Land use planning - By consulting the database early in the planning process, planners and engineers can avoid costly conflicts. The Natural Heritage Database can determine whether the intended project area includes locations of endangered or threatened species or exceptional natural features.

Impact assessment, environmental review, permit review - A quick initial assessment from the database speeds up the review process.

Natural area selection, design and stewardship - Conservationists can use the database to focus efforts on preserving the most critically endangered natural heritage features of our state.

Resource Management - Information used to improve existing management policies and practices.

Research and Education - Data will help guide new research and provide a long-term educational resource.

Database Limitations

The quantity and quality of data collected by the Natural Heritage Database depend on the research and observations of many individuals and organizations. Reports generated from the Natural Heritage Database summarize the existing information regarding the biological elements or locations in question known at the time of the request. These reports should never be regarded as final statements on the elements or areas being considered, nor should they be substituted for on-site surveys required for environmental assessments.

What Information is Available?

For any specified area of Illinois, the Natural Heritage Database can provide the following information:

Plants and Animals: Almost 500 species that are either:

  • on Illinois' official list of endangered and threatened species
  • on the federal list of endangered and threatened species

Natural Communities: high-quality communities of statewide significance

Other Special Features: nesting of colonial birds, unique geological features, large forest blocks, etc.

Natural Areas: areas on the Illinois Natural Areas Inventory

Managed Areas: Nature Preserves, Land and Water Reserves, Natural Heritage Landmarks.

What Data Formats are Available?

The data management system, which includes both computer and manual components, is designed to generate reports in a variety of formats according to the user's needs. Users may request data organized by the following categories:
Geographic Area: county, U.S. Geological Survey topographical quadrangle maps, river drainage, managed area

Type of Natural Community: forest, prairie, wetland

Species or Feature: federal- or state-listed endangered or threatened species, rookeries...

Of course, requests for data may specify two or more criteria: for example, all state-listed birds in Lake County.

How Can You Request Information?

Perspective data users should contact:

Illinois Natural Heritage Database
Illinois Department of Natural Resources
ORC - Division of Habitat Resources
One Natural Resources Way
Springfield, IL 62702

All requests for information must be submitted in writing. Requests should include a description of what data is needed, a statement explaining how the information will be used and background material that will aid in filling the request (i.e. maps, project descriptions, etc.). Normally, users will receive the requested data within 2 - 3 weeks.


Scientists, resource managers, and volunteers contribute to the database. Major contributors include:

  • Illinois Department of Natural Resources
  • The Nature Conservancy
  • Illinois Natural History Survey
  • The Morton Arboretum
  • Southern Illinois University-Carbondale
  • Eastern Illinois University
  • Illinois State Museum
  • Illinois Nature Preserves Commission
  • Illinois Endangered Species Protection Board



Link to State of IL Home PageLink to Email ContactsLink to IDNR's FAQs Page