Low Elevation
< 435 feet above mean sea level
Low Place
Illinois River
Low Quad Name
Clear Lake
Low PLSS
3-5-19N-11W
Low Geology
Cahokia Alluvium, river valley
High Elevation
> 730 feet above mean sea level
High Place
2 unnamed hills along a ridge
High Quad Name
Easton
High PLSS
3-25-20N-7W
High Geology
Parkland sand ridges
Area
557.44 square miles
Total Relief
295 feet
Percent Slope
0.54%