An aquatic habitat classification system for the UMRS Wilcox, D. B. 1993. An aquatic habitat classification system for the Upper Mississippi River System. U.S. Fish and Wildlife Service, Environmental Management Technical Center, Onalaska, Wisconsin, May 1993. EMTC 93-T003. 9 pp. + Appendix A. (NTIS # PB93-208981) ABSTRACT A classification system for aquatic habitat in the Upper Mississippi River System (UMRS) is needed for inventory, research, impact assessment, and management purposes. The comprehensive system of aquatic habitat classification proposed here has a hierarchical structure to facilitate habitat mapping and inventory at different spatial scales and varying levels of resolution. The classification system is based on geomorphic features of large floodplain rivers, constructed features of the UMRS, and physical and chemical characteristics of aquatic habitat. KEYWORDS aquatic habitat, classification, Upper Mississippi River, Illinois River, geomorphology