National Wetlands Inventory - Wetlands

This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Trust Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). Certain wetland habitats may be excluded because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition.   The U.S. Fish and Wildlife Service (Service) is the principal Federal agency that provides information to the public on the extent and status of the Nation's wetlands.  The Service's strategic plan for our vast national wetland data holdings is focused on the development, updating, and dissemination of wetlands data and information to Service resource managers and the public.  The development of the Wetlands Master Geodatabase is in direct response to the need to integrate digital map data with other resource information to produce timely and relevant management and decision support tools.  

Due to the quantity and complexity of the data, wetlands and riparian data only displays at 1:250,000 scale and greater. For wetland information visit www.fws.gov/wetlands/