US Army Corps of Engineers
Rock Island District Website


Why the Upper Mississippi River Matters

The Upper Mississippi River System (UMRS) is one of this nation’s unique natural resources.  The UMRS is one of a small number of large river floodplain ecosystems still characterized by annual flood pulses that advance and retreat over the floodplain and temporarily expand backwaters and floodplain lakes.  The UMRS floodplain ecosystem provides habitat for a wide array of fish and wildlife species distributed among a complex arrangement of flowing channels, floodplain lakes, backwaters, wetlands, and floodplain forests.  The river supports a diverse mussel fauna, contains more than 25 percent of North America’s freshwater fish species, and is an internationally recognized flyway for migrating birds.