From the Scout Report, University of Wisconsin, July 31, 2009:
"The U.S. Fish and Wildlife Service is the primary federal agency that provides information on the state of the country’s wetlands, and this site provides extensive geospatial data on their current extent and location." Highly productive ecosystems, wetlands are so important in providing habitat and renewal of groundwater. There is a "Wetlands Mapper" and images from Google Earth. Digital wetlands data is downloadable by state or quadrant.
The UNEP has added another to its panoply of resources: The Global Resource Information Database (GRID) has been developed by the USGS EROS Data Center and Google Maps by employing remote sensing, geographic information systems (GIS), and online mapping tools to create this free resource for use of geographers, political scientists, environmental researchers and policy decision-makers. “The atlas highlights sites around the world that have witnessed such dramatic environmental changes as glacial melt, desertification, deforestation, pollution, and population growth.”
Source: “Best Free Reference Websites, Ninth Annual List”, Reference & User Services Quarterly, Vol. 47(1), Fall, 2007.