Lowest and Highest Points in Johnson County
Low elevation: <330 feet above mean sea level
Place: Cache River
7.5' quadrangle name: Cyress
PLSS: 4-18-14S-2E
Geology: Cahokia Alluvium in river valley
High elevation: 850 feet above mean sea level
Place: unnamed hilltop
7.5' quadrangle name: Lick Creek
PLSS: 3-18-11S-2E
Geology: Pennsylvanian Caseyville Sandstone ridge
Area: 345.03 square miles
Total relief (approximate): 520 feet
Average percent slope: 3.01%
Updated 9/30/2009 JKH