The U.S. Army Corps of Engineers' Upper Mississippi River Restoration (UMRR) program, through its Long Term Resource Monitoring (LTRM) element, collected aerial imagery of the systemic Upper Mississippi River System (UMRS) during the summer of 2020. A Land Cover/Land Use (LCU) spatial database was developed based on the 2020 aerial imagery, which adds a fourth systemic-wide database to the existing 1989, 2000, and 2010/11 LCU databases. These data have been used to create a variety of products, one of which is a data set used to classify aquatic areas. The 2020 aquatic areas data sets were created by first generalizing the available land cover/use data into a land/water data set, then reinterpreting the areas classified as water to determine the type of aquatic area. Area coverage for this data set is the Upper Mississippi River between Minneapolis, MN and Cairo, IL, and the Illinois River from its confluence with the Mississippi to Joliet, IL.