The physico-chemical characteristics of ponds of three strip-mine areas in Southern Illinois were observed under both winter and summer conditions. In addition to a general discussion of the areas, a detailed report is made on dissolved oxygen as associated with thermal stratification, and on pH and specific conductance. Observations were also made on the plant life and fishes of the ponds. The more important findings included high concentrations of dissolved oxygen in the thermocline, pH values ranging from 3 to 8, and extremely high specific conductance. Chemical conditions were not associated with the age of the ponds. The ponds have many characteristics of oligotrophic lakes and the possibilities for fish production are limited. The most common fishes of the ponds were the green sunfish (Lepomis cyanellus), bluegill (Lepomis macrochirus), and largemouth bass (Micropterus salmoides). Some ponds were devoid of fish life.