The U.S. Geological Survey's Upper Midwest Environmental Sciences Center (UMESC) has created high-resolution land cover/use data sets for the Upper Mississippi River System (UMRS) from 1:15,000-scale color infrared aerial photos. These data have been used to create a variety of products, one of which is a data set used to classify aquatic areas. The geographic extent of the UMRS is the Mississippi River floodplain from Cairo, IL to Minneapolis, MN and the Illinois River floodplain from its confluence with the Mississippi near Grafton, IL to Lake Michigan.