Lowest and Highest Points in Mercer County
Low elevation: <530 feet above mean sea level
Place: Mississippi River
7.5' quadrangle name: Keithsburg
PLSS: 4-34-13N-5W
Geology: Cahokia Alluvium in river valley
High elevation: >820 feet above mean sea level
Place: Unnamed hilltop
7.5' quadrangle name: Reynolds
PLSS: 4-5-15N-2W
Geology: Illinois Vandalia till member upland
Area: 562.12 square miles
Total relief (approximate): 290 feet
Average percent slope: 1.35%
Updated 10/1/2009 JKH