National Wetlands Inventory of the United States - State and Substate Shapefiles

Data downloaded from original source at https://www.fws.gov/wetlands/data/State-Downloads.html by State.  The data is downloaded as a .zip file that contains the following layers:

• Wetlands polygon data
• Wetlands Project Metadata (includes image dates and project information)
• Wetlands Historic Map Information*
• Riparian polygon data*
• Riparian Project Metadata (includes image dates and project information)*
• Historic Wetlands*
• Historic Wetlands Project Metadata (includes image dates and project information)*

* If available at the requested location.

Information about each of these layers can be found on the NWS Metadata page.     

Detailed documentation of the Cowardin Classification system can be found on the NWS Wetland Code page. There you can also download the NWI Code Definitions Table that provides users with the full wetland or deepwater habitat description within their own mapping application.