National Wetlands Inventory
Ecological Services

Frequently Asked Questions

Wetlands Data

Wetlands Mapper




How can I view wetland data? 

Visit our wetlands mapper. The mapper hosts the most current digital wetlands data held by the U.S. Fish and Wildlife Service, National Wetlands Inventory.

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Can I download the wetlands data?

There are two methods for downloading seamless wetlands data as viewed on the Wetlands Mapper:

  • Each State data set is available for download as either a compressed file Geodatabase or a Shapefile.
  • The Wetlands Mapper Download Data by Extent tool uses the Wetlands Mapper to create a ZIP file containing a compressed file Geodatabase and a Shapefile of the current visible extent. A web link for downloading the file will be sent by email. This tool is available by visiting the Wetlands Mapper, zooming to an area of interest, then selecting the Download Data in Current Extent tool (Tools menu).

In addition, the wetlands data may be viewed in many GIS software applications using the Web Map Service (WMS). Instructions on how to add the WMS layer can be found on the wetlands WMS website.

The wetlands data can also be viewed with the Google Earth application. Instructions on how to add the wetlands data to Google Earth can be found on our Google Earth web page.

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What software do I need to view the downloaded data?

Shapefiles can be viewed using most GIS software applications, including ESRI's free ArcGis Explorer software. Geodatabases will require ESRI software (version 10.*) to view.

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I have downloaded the State data from this website, but I get an error when I try to unzip the file.

If an error occurs during your download, or if your downloaded file(s) is corrupted, we strongly recommend the use of a download manager. A download manager is a computer program dedicated to the task of downloading files from the Internet for storage. The typical download manager at a minimum provides means to recover from errors without losing the work already completed.

There are several download manager programs available, including some that are free. We use Xtreme Download Manager (Open Source software); it works really well.

Note: Due to their size, State files can not be sent by email. For security reasons, we are not allowed to serve data via FTP.

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How do I save (PDF format) and print a map?

To save a map to your hard drive:

  1. On the wetlands mapper, zoom to an area of interest and turn on layers of interest.
  2. Click on the 'Print Map' button in the upper right hand corner of the Mapper.
  3. Position and scale the map in the window provided to ensure the printed product will contain the desired area.
  4. Add a Title and/or Remarks in the form in the upper right hand corner.
  5. Click on the Submit button.
  6. Wait a few seconds for the PDF to be created.
  7. Your computer should then pop-up a 'Save As' window which allows you to save the PDF to your computer.
  8. If you wish to print your map, open the previously saved PDF file, and select the menu item File, then Print.

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Can I download larger areas of wetland data?

Currently the only way to obtain the wetlands data set is by using the Wetlands Data download web page.

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How far do I have to zoom in to be able to see the wetlands polygons?

Wetlands will first display at a scale of 1:144,448. The nominal scale for viewing and using wetlands data is 1:12,000 or 1:24,000, although higher resolutions are possible.

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How do I enter a latitude and longitude coordinate?

The 'Find Location' tool in the Wetlands Mapper accepts decimal degrees for coordinates separated by a comma in Long/Lat format (e.g. -89.4676, 43.0568). 

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How can I find out what a wetland map code means?

Visit the Wetland Code Interpreter and type in the case-sensitive code. For example, entering code PUBHh will result in the wetland explanation for Palustrine, Unconsolidated Bottom, Permanently Flooded, Diked/Impounded wetland. Wetland Codes are also explained in the Map Code Diagram (PDF), which outlines the classification system by system, subsystem, class, subclass, plus modifiers. The wetland codes are based on the National Wetlands Classification Standards from Cowardin, L.M., V. Carter, F. Golet, and E. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States 2nd Edition (1.4MB PDF). U.S. Fish and Wildlife Service.

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What do the two categories under Wetlands Data Availability mean?

Digital Data: Wetlands digital data are available and currently being displayed on the Wetlands Mapper. 
No Data: FWS has not mapped wetlands in these areas.

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Where can I find metadata for wetland digital data and other data sets displayed on the Wetlands Mapper?

Metadata information can be found on the Wetlands Product Summary page. Metadata files for all the layers displayed on the Wetlands mapper can be found at the metadata web page. You can also visit our wetlands mapper; the mapper hosts the most current digital data and metadata available.

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What is the intended use of the Wetlands Mapper?

The principal focus was to produce topical wetland maps that are graphic representations of the type, size and location of all surface waters in the United States (wetlands and deepwater habitats). Within this context, the objective of mapping wetlands and deepwater habitats remains to produce reconnaissance level information on the location, type and size of these habitats such that they are accurate at the nominal scale of the 1:24,000 base map. The Service recognized the limitations of using remotely sensed information as the primary data source, and additionally, by policy, excluded some wetland types from its inventory.  See the Product Summary web page for more information.

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Does the wetlands mapper display all wetland polygons from the Wetlands Geodatabase?

Yes. All available wetland map data are displayed on the Mapper.

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What are the Areas of Interest?

This layer was designed to highlight wetlands that exhibit unique or important ecological characteristics. It currently includes sites located throughout the United States. It includes Wetlands of International Importance (Ramsar sites) as well as state natural areas, National Parks and National Wildlife Refuges. Each site is marked with a geographic location and includes a link to additional information about that particular wetland. Additional site and information will be added in the future.

This dataset is not meant to be inclusive, contains only a small representative sample of wetland areas and will be updated periodically.

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Why is the Wetlands Mapper not displaying data nor printing my map?

This problem could be caused by old internet addresses in your browser and/or computer DNS cache. To clear both, please do the following in this order:

1. Open a Command Prompt window (Start button, Search box, type Command Prompt).
2. tyoe  ipconfig /flushdns  and press Enter. (if unsuccessful, you may have to do this with Admin rights).
3. Restart your computer.
4. Open your browser, then clear your cache memory.
5. Open the mapper from here:
6. If the steps above do not solve your problem, please try our new HTML5 (non-Flash) beta version of the Wetlands Mapper. The link to the new beta Mapper is below the blue box.

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Is the Wetlands Mapper the only place I can view U.S. Fish and Wildlife wetland data?

The wetlands data may be viewed in many GIS software applications using the Web Map Service (WMS). Instructions on how to add the WMS layer can be found on the wetlands WMS website. The wetlands data can also be added to the Google Earth application using a prepared KMZ file. Instructions on how to add the wetlands data to Google Earth can also be found here.

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Can the Wetlands Mapper be used for legal or regulatory purposes regarding wetland location or identification?

The U.S. Fish and Wildlife Service (FWS) neither designed nor intended the National Wetlands Inventory program to produce legal or regulatory products. Unintended use of the information or products is discouraged. Federal, State, and local regulatory agencies with jurisdiction over wetlands may define and describe wetlands in a different manner than that used in this inventory. There is no attempt, in either the design or products of this inventory, to define the limits of proprietary jurisdiction of any Federal, State, or local government or to establish the geographical scope of the regulatory programs of government agencies. Persons intending to engage in activities involving modifications within or adjacent to wetland areas should seek the advice of appropriate Federal, State, or local agencies concerning specified agency regulatory programs and proprietary jurisdictions that may affect such activities.

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How do I cite wetland digital data or hard-copy maps in publications?

For wetland digital data downloaded from our website: U. S. Fish and Wildlife Service. Publication date (found in metadata). National Wetlands Inventory website. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C.

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When were wetlands in my area mapped?

The Service's topical wetland and riparian maps are graphic representations of the type, size and location of the wetlands, deepwater or riparian habitats in the United States. These maps have been prepared from the analysis of high altitude imagery in conjunction with collateral data sources and field work. The date a given wetland polygon is valid is based on the imagery that was used for the interpretation. This imagery information is visible when you click on a wetland polygon in the Wetlands Mapper. A display box containing information about the selected polygon will appear including 'Image Date(s)' which identifies the year(s) of imagery used. For a more general view of when the wetlands in a larger area were mapped display the' Data Source - Image Year' layer on the Wetlands Mapper.

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What is the map projection for State downloads?

State data downloaded will be in Albers projection with a Geographic Coordinate System of  North American Datum (NAD) 1983.

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Why is my location button not working in the new wetlands mapper for mobile devices?

The zoom to location will not work on your mobile device unless the location services are turned on. Each device may have different ways to accomplish this. For Apple devices, follow this link. For Android devices, please follow this link. Certain browsers have specific location settings: for Safari, please follow this link; for Chrome, please follow this link.

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Where can I find the National List of Vascular Plant Species that Occur in Wetlands?

The responsibility to maintain and update the Plant List was transferred to the U.S. Army Corps of Engineers (Memorandum of Agreement) (PDF) (December, 2006).

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Whom do I contact when I have a question?

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Last updated: May 27, 2016