Low Elevation
< 518 feet above mean sea level
Low Place
Mississippi River
Low Quad Name
Dallas City
Low PLSS
4-34-8N-7W
Low Geology
Cahokia Alluvium, river valley
High Elevation
> 800 feet above mean sea level
High Place
unnamed hilltop
High Quad Name
Raritan
High PLSS
4-25-8N-4W
High Geology
Thin Illinois Kellerville till upland over Pennsylvanian Carbondale Formation
Area
391.97 square miles
Total Relief
282 feet
Percent Slope
1.04%