Lowest and Highest Points in Jo Daviess County
Low elevation: <590 feet above mean sea level
Place: Mississippi River
7.5' quadrangle name: Green Island
PLSS: 4-31-26N-2E
Geology: Cahokia Alluvium in river valley
High elevation: 1235 feet above mean sea level
Place: Charles Mound
7.5' quadrangle name: Shullsburg
PLSS: 4-13-29N-2E
Geology: Silurian limestone hill
Area: 613.63 square miles
Total relief (approximate): 645 feet
Average percent slope: 4.25%
Updated 9/30/2009 JKH