U.S. Fish & Wildlife ServiceThis layer represents the boundary of the Chesapeake Bay watershed. The Chesapeake Bay is the largest estuary in the U.S. and supports roughly 3,600 species of plants and animals, including 348 species of finfish, 173 species of shellfish, and 2,700 species of plants. Nearly one million waterfowl winter on and near the bay - approximately one-third of the Atlantic Coast's migratory population. The birds stop to feed and rest during their annual migration along the Atlantic Flyway. This boundary was extracted from the USGS Watershed Boundary Dataset using the hydrologic unit codes (HUCs) by the US Fish and Wildlife Service for use in the Chesapeake Watershed Investments for Landscape Defense Program, known as Chesapeake WILD. F or more information on Chesapeake WILD visit https://www.fws.gov/program/chesapeake-wild . HUCs have two to eight digit numbers based on the four levels of classification in the hydrologic unit system. The Chesapeake Bay watershed is delineated in the HUC 4 (four digit) layer. For more information about hydrologic units visit https://water.usgs.gov/GIS/huc.html .ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/4f0335d5124d4e2c9fc5f189bb97ad06_0engU.S. Fish and Wildlife Service Open DataPublicChesapeake Bay Watershed Boundary [United States]Web servicesUnited StatesLast Modified: 2023-05-15