Enhanced Historical Land-Use and Land-Cover Data Sets of the U.S. Geological Survey: polygon format files

This data set depicts land use and land cover from the 1970s and 1980s
and has been previously published by the U.S. Geological Survey (USGS)
in other file formats. This version has been reformatted to other file formats
and includes minor edits applied by the U.S. Environmental Protection
Agency (USEPA) and USGS scientists. This data set was developed to
meet the needs of the USGS National Water-Quality Assessment (NAWQA)
Program.