Connecticut Department of Energy & Environmental Protection

Natural Diversity Data Base Maps

The Natural Diversity Data Base (NDDB) maps show approximate locations of endangered, threatened, and special concern species and important natural communities in Connecticut. General locations of species and communities are shown as shaded areas ("blobs") on the maps. Exact locations are masked to protect sensitive plants and animals from collection and disturbance and to protect landowner’s rights.

The locations shown are based on information collected over the years by DEEP staff, conservation groups, landowners, and the scientific community. Some locations are based on historic records. Unmapped areas are not an indicator of species absence and may contain potential habitat that has not been adequately surveyed for all taxa.

New information is added to the data base continually and used to update the maps periodically. Residents are welcome to submit new information for review.

The purpose of NDDB maps

The maps are intended to highlight known locations of state-listed species in order to avoid potential impacts and to assist with regulatory compliance. They can also highlight potential areas for habitat conservation or restoration. The NDDB maps are updated twice a year, generally in June and December. Be sure to check this webpage regularly and use the newest versions of maps for your project screening requirements. The maps currently listed here were updated in December 2025.

How to access the maps

NDDB Maps by Town (updated December 2025)

From your computer: You can view or download current individual town maps listed below. Microsoft Edge is the recommended browser.

If you have trouble, you can also try accessing the maps from the Connecticut Environmental Conditions Online Map Catalog or in the interactive CTECO Advanced map viewer (turn on layers in the Bioscience category)

From a public computer: There is a public computer available in the DEEP Public File Room at 79 Elm Street in Hartford. 

Other related maps

Northern Long-eared Bat Map

Northern Long-eared Bat - Additional information from the U.S. Fish and Wildlife Service

Surface Water Discharge NDDB Screening Map (formerly Freshwater Mussel Map)

Instructions for Review of Surface Water Discharge NDDB Screening Map

Download NDDB GIS Data

NDDB maps by town 

Find towns by alphabet: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

B

C

D

E

F

G

H

K

L

M

N

O

P

R

S

T

U

V

W

Content last updated in March 2026.