Low Elevation
< 440 feet above mean sea level
Low Place
Illinois River
Low Quad Name
Henry
Low PLSS
3-33-31N-2W
Low Geology
Cahokia Alluvium, river valley
High Elevation
> 740 feet above mean sea level
High Place
unnamed hilltop
High Quad Name
McNabb
High PLSS
3-17-32N-1W
High Geology
Mount Palatine Moraine
Area
170.51 square miles
Total Relief
300 feet
Percent Slope
1.77%