Union County State Fish & Wildlife Area, at the southwestern tip of the state, encompasses 6,202 acres in the Lower Mississippi River bottomlands division of Illinois.
Numerous shallow sloughs and other water areas totaling approximately 1,100 acres are scattered throughout the conservation area. The most prominent bodies of water include Grassy Lake with 350 acres and Lyerla Lake with 275 acres. Of the 5,350-acre land area, approximately 2,400 acres are cultivated. The remaining acreage is timber, brush or permanent grass cover. By far the most intensive activity on the area is farming. Each year a variety of hard grain and green forage crops are planted and left standing to provide food for wintering geese.
The Illinois Department of Natural Resources acquired Union County Conservation Area in the late 1940s to create wintering goose population, which reached in excess of 50,000 birds by 1964.
Union County State Fish & Wildlife Area provides habitat for large concentrations of migratory and overwintering waterfowl, especially Canada, Greater White-fronted and Snow Geese. Lesser numbers of Ross's and Cackling Geese also use the site. Migratory and wintering ducks include Gadwall and Mallard, among other puddle ducks. The large numbers of waterfowl attract predatory Golden and Bald Eagles.
Other migrants that use the area for foraging and resting include American Coot; American White Pelican; Little Blue Heron; Black-crowned Night-Heron; Yellow-crowned Night-Heron; Great, Snowy and Cattle Egrets; Great Blue Heron; and American and Least Bitterns.
Due to the varied habitat, migrating birds of many different families have been documented here, including warblers, vireos, tanagers, thrushes, swallows, shorebirds and even Osprey, Upland Sandpiper and Bobolink.
Breeding species include Mississippi Kite, Yellow-crowned Night-Heron, Least Bittern, Red-shouldered Hawk, Bald Eagle, Pileated Woodpecker, Red-headed Woodpecker, Loggerhead Shrike, Fish Crow, Orchard Oriole,
Blue Grosbeak, Prothonotary Warbler, American Redstart and Pied-billed Grebe.
Least Terns forage on the refuge, coming from nearby breeding sites.
This site was chosen as an IBA because it met the criteria for congregations of Waterfowl, breeding Mississippi Kite and Prothonotary Warbler, and congregations of wintering Rusty Blackbirds.
This area is located in the Lower Mississippi River Bottomlands Division of Illinois. The topography is relatively flat with numerous shallow sloughs and other water areas scattered throughout the area. More prominent water areas include Grassy Lake with 350 acres and Lyerla Lake with 275 acres.