Lowest and Highest Points in McDonough County
Low elevation: <500 feet above mean sea level
Place: Camp Grindstone Creek
7.5' quadrangle name: Fandon
PLSS: 4-36-15S-4W
Geology: Cahokia Alluvium in river valley
High elevation: >800 feet above mean sea level
Place: Unnamed hilltop
7.5' quadrangle name: Raritan
PLSS: 4-7-7N-3W
Geology: Thin Illinois Kellerville till over Pennsylvanian Carbondale Formation
Area: 583.92 square miles
Total relief (approximate): 300 feet
Average percent slope: 1.13%
Updated 10/1/2009 JKH