Southwestern Illinois, which includes Kaskaskia River SFWA, has traditionally been rich in fish and wildlife resources and was occupied by both American Indians and early settlers to the state. The Kaskaskia River remained essentially unchanged until the late 1960s when it was modified by channelization to promote commercial development and navigation. This led to eventual state ownership of the site and increased the public use of the area.
Kaskaskia River SFWA possesses a wide variety of terrestrial and aquatic habitats. Water acres include not only the Kaskaskia River with its associated side channel and backwater areas (2,200 acres), but also Baldwin Lake (2,018 acres) and Peabody-River King State Fish and Wildlife Area (2,200 acres).
A land area of about 16,000 acres includes an extensive mixed bottomland forest comprised of pecan, soft maple, bur oak, pin oak, shellbark hickory and willow. Many cultivated and fallow fields, native grass patches, brushy areas and other "open" areas are interspersed with the stands of mature bottomland timber. Due to this great diversity of habitats, good wildlife populations exist on the site.
Power plant operation noticeably influences fish activity and fishing success. Fishes in Baldwin Lake experience a longer growing season than do those in surrounding lakes, therefore growth rates are accelerated for certain species. Fishing at Baldwin Lake is good year round and is very popular during the winter months. Warm water areas of the lake may have temperatures in the 60's even in late January.
To maintain a stable elevation throughout the year, water from the nearby Kaskaskia River is pumped into the lake periodically. The lake averages a depth of 8 feet, however old creek channels and ponds provide areas of 20 to 50 feet in depth.
Baldwin Lake and the adjoining lands are designated as a waterfowl and wildlife refuge. During the winter, peak populations of 10,00 geese and 20,000 ducks may be seen on the area. Waterfowl viewing is a popular activity along the waterfowl refuge drive. There are approximately 200 resident giant Canada geese on the area which nest on the lake levees. Broods of goslings may be seen on the area beginning in late April. Various other species of wildlife may also be observed along the refuge drive including white-tailed deer, shorebirds, wild turkeys, hawks, and various songbirds.