The Carrier Mills Archaeological District covers some 143 acres about two miles south of Carrier Mills and was inhabited by prehistoric people during three different archaeological periods. Before the turn of the century, the South Fork of the Saline River was a meandering stream with nearby swamps and shallow cypress lakes rich in plants and animals, making the locality a natural focal point for human settlement. Intensive archaeological investigations in 1978 and 1979, aided by excellent preservation conditions, recovered many tools and animal and plant remains that provided significant new insights into the prehistory of southern Illinois. Small groups of hunters and gatherers used the area sporadically by 8000 B.C., and it remained in use more or less continuously until 1400 A.D. Settlement increased dramatically during the late Middle Archaic Period, 4500 to 3000 B.C., when larger groups with a more sedentary lifestyle left thick deposits containing many artifacts and burials. The area also saw heavy use during the Middle and Late Woodland periods, 200 B.C. to A.D. 900, when people increasingly collected and stored plant foods and began to domesticate some native plants. The final prehistoric inhabitants were Mississippian Period Indians, from A.D. 900 to 1400, who lived in scattered farmsteads and cultivated corn and squash.