The Upper Mississippi River Waterfowl Conservation Region (Region 19*) includes portions of the Eastern Tallgrass Prairie, Prairie Hardwood Transition and the Central Hardwoods of the Commission for Environmental Cooperation (IAFWA 1998). This region is bisected by the floodplain of the Mississippi River and its larger tributaries in all states of the watershed. The floodplains of the river systems include diverse wetland habitat, including temporarily and seasonally flooded bottomland hardwoods, permanently and semi-permanently flooded shrub and wooded swamps, emergent wetlands, mudflats and submerged aquatic beds, all of which are utilized by migrating waterbirds.
The Mississippi River and its major tributaries, the St. Croix, Chippewa, Wisconsin, and Rock Rivers, drain approximately 75% of Wisconsin's landscape. The Upper Mississippi River basin in Wisconsin has nearly 38,057 ha of riverine and bottomland habitat, 371 km river length, and almost 3,226 km of shoreline (USFWS 1998). This region provides important wildlife habitat and is vital to maintenance of water quality. Southeast Wisconsin contains the largest cattail marsh in the U.S., Horicon Marsh. Horicon Marsh is nearly 12,955 ha in size and is designated a RAMSAR Wetland of International Importance. Additionally, more than 35,830 ha are protected under public ownership in the Mississippi River and Trempleau NWRs.
Except for a small portion of the Chicago metropolitan area, all of Illinois occurs in the watershed of the Mississippi River. Approximately 90% of historic wetlands of Illinois have been lost (Dahl 1990). A major portion of Illinois that drains into the Mississippi River comes through the Illinois River Valley. Prior to settlement, the Illinois River basin contained approximately 141,700 ha of wetlands, but now less than 68,826 ha remain due primarily to drainage for agriculture. State and federal management areas protect 6,680 ha of existing habitat, and private duck clubs have secured an additional 6,478 ha (USFWS 1998). Because 80% of the watershed is used for agriculture, high erosion rates have impacted terrestrial and aquatic waterfowl habitat as well as water quality.
The Mississippi River Valley in southern Illinois contains more than 137,651 ha of wetlands. Along the Cache River, swamps, bottomland forests, limestone glades and success ional fields provide habitat for over 250 species of migratory waterfowl, wading birds and Neotropical migrant songbirds (USFWS 1998). This area has been designated as a wetland of international importance by the RAMSAR convention. Black Bottom, located at the southeastern tip of Illinois on the north side of the Ohio River contains low gravel hills with continual groundwater seeps. The area is rich in a diversity of unique flora, including cypress swamps, flood plain forests and rare species of orchids, mosses and ferns. Predominantly in private ownership, this unique wetland complex should be preserved for its integrity and benefit to all types of wetland bird species. Timber harvest, levee construction and surface mining have altered habitat conditions for migratory waterfowl and other wildlife in this region of Illinois.
Wetland loss in Indiana has been extreme with only 15% of the state's pre-settlement wetlands remaining (Dahl 1990). Clearing bottomland forests in southwest Indiana has been the primary impact on wetland habitat. Few flood control levees exist in southern Indiana, allowing rivers to flood over their banks and into the bottomlands in spring and fall. However, frequency and intensity of flooding events have been affected by agricultural and other human development. Threats to wetlands in this area include agricultural activities, commercial and residential development, road building, water development projects, timber harvest, mining, groundwater withdrawal and vegetation removal and sedimentation.
In addition to being dominated by the large river systems of the Ohio, Wabash, White and Patoka, the Indiana portion of this region also includes the Kankakee River basin in northeast Indiana, which once supported one of the largest freshwater wetland complexes in the U.S. (USFWS 1998). Known as the Grand Kankakee Marsh, this area once encompassed over 202,429 ha of prime waterfowl habitat. Wetland and prairies were intertwined with the Kankakee River as it meandered from South Bend, Indiana to the Illinois state line, taking a 387 km course to cover the 121 km distance. Channelization and drainage to support agriculture have resulted in the loss of nearly the entire marsh.
*Region 19 - NABCI Bird Conservation Regions 22, 23 & 24 (E astern Tallgrass Prairie, Prairie Hardwood Transition, Central Hardwoods)