The Kaskaskia River Corridor encompasses five Illinois counties in southwestern Illinois. The corridor is a complex of interconnected floodplain forests, wetlands and flatwoods. The largest tract of contiguous forest in Illinois can be found here.

Ornithological Summary

Uninterrupted tracts of forested bottomland attract breeding Cerulean Warbler and Brown Creeper to this river corridor.

Colonial breeders here include Snowy Egret, Little Blue Heron, Great Egret, Great Blue Heron and Black-crowned Night-Heron.

This site was chosen as an IBA because it met the criteria for breeding Brown Creeper, Cerulean Warbler, and Prothonotary Warbler.


Property along the Kaskaskia River Corridor is in a variety of holdings. The area consists of 10 State Natural Areas, 31.1 miles of Biologically Significant Stream, 28 Natural Heritage Sites, one State Park, one State Fish & Wildlife Area, and some Federal Land. The remainder of the land is in private ownership.


The extensive Kaskaskia River Corridor contains 6,700 acres of upland forest, 35,540 acres of bottomland forest, 1,448 acres of wetlands, 31,689 acres of grassland and roughly 115,000 acres of cropland. About 3,000 acres of open water is also contained within the corridor along with an urban residential area of about 4,000 acres.

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