Extent of available data.
Minnesota's statewide National Wetland Inventory was developed between 1980 and 1986. Wetlands were primarily identified through aerial photo interpretation. Limited field verification and the use of supplemental spatial data, primarily USGS Quadrangle Maps and soil surveys, aided the process. Wetlands are highly valued for their ecological contributions They provide habitat for a variety of plants and animals and improve water quality. Minnesota's wetlands are also legally protected - any loss of wetlands in the state must be mitigated through an associated restoration project.