Lowest and Highest Points in Rock Island County

Lowest and Highest Points in Rock Island County
Low Elevation: 
<540 feet above mean sea level
Low Place: 
Mississippi River
Low Quad Name: 
Blanchard Island
Low PLSS: 
4-34-16N-6W
Low Geology: 
Cahokia Alluvium
High Elevation: 
>810 feet above mean sea level
High Place: 
unnamed hilltop
High Quad Name: 
Reynolds
High PLSS: 
4-31-16N-2W
High Geology: 
Illinoian Kellerville till upland
Area: 
447.32 square miles
Total Relief: 
270 feet
Percent Slope: 
1.50%