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Natural Diversity Data Base (NDDB) Maps

The Natural Diversity Data Base maps represent approximate locations of endangered, threatened, and special concern species and significant natural communities in Connecticut. The locations of species and natural communities depicted on the maps are based on data collected over the years by DEEP staff, scientists, conservation groups, and landowners. In some cases, an occurrence represents a location derived from literature, museum records and specimens. These data are compiled and maintained by the Natural Diversity Data Base.

The maps are intended to be a pre-screening tool to identify potential impacts to state-listed species. These data are also used by groups wishing to identify areas of potential conservation concern. The maps are updated periodically (every 6 months or so) and new information is continually being added to the database. It is important to always use the most current version for your planning needs.

Maps were originally distributed to all town planners as part of the Mapping for Municipalities project which was aimed at providing towns with a tool for including endangered species reviews in their local land use planning efforts. The availability of these maps online and in digital formats has allowed DEEP to reach a wider audience. The DEEP encourages local officials and citizens to use this important information.

The general locations of species and communities are symbolized as shaded areas ("blobs") on the maps. Exact locations have been masked to protect sensitive species from collection and disturbance and to protect landowner’s rights whenever species occur on private property.  A new mapping format was employed in 2012 that more accurately models important riparian and aquatic areas and eliminates the need for the upstream and downstream searches required in previous versions.  Please read the map instructions carefully as they have changed.

Other features, including political boundaries and hydrography data on the maps, are based on the U.S. Geological Survey 7.5 Minute topographic maps. Streets and street names are provided by Tele Atlas. The base map data may be neither current nor complete.

View Maps by Town

Instructions for Viewing/Downloading Maps: Different browsers and download settings may affect the behavior of the download. The map download will attempt to open using your default browser and download settings. Microsoft Edge is recommended for downloading maps from this site. Users experiencing problems with the download can try accessing NDDB maps from the Connecticut Environmental Conditions Online website run by UCONN CLEAR and DEEP at ; PDF maps can be found in the Map Catalog section.

If you plan on viewing this map more than once, you may want to download it to your computer. Right click on the "Download Map" link. Select "Save Target As" from the drop-down menu. You will be prompted for the location on your computer where you would like to save the file. Navigate to the appropriate location and select "Save". Be sure to make a note of the file name for future file retrieval. After the save is complete, you can view the map by double clicking on the file name in "My Computer" or Windows Explorer.

Northern Long-eared Bat Map

Additional USFWS Information on Northern Long-eared Bats and the Final 4(d) Rule

NDDB Freshwater Mussel Map

Instructions for Review of NDDB Freshwater Mussel Map

Download NDDB GIS Data

Order Printed NDDB Maps from the DEEP Store

Content last updated on March 9, 2021.