Lowest and Highest Points in St. Clair County
Low elevation: <360 feet above mean sea level
Place: Kaskaskia River
7.5' quadrangle name: Red Bud
PLSS: 3-32-3S-7W
Geology: Cahokia Alluvium in river valley
High elevation: >700 feet above mean sea level
Place: Unnamed hilltop
7.5' quadrangle name: Columbia
PLSS: 3-13-1S-10W
Geology: Vandalia till uplands over Mississippian Upper Valmeyeran
Area: 666.66 square miles
Total relief (approximate): 340 feet
Average percent slope: 0.99%
Updated 10/1/2009 JKH