Low Elevation
< 590 feet above mean sea level
Low Place
Mississippi River
Low Quad Name
Green Island
Low PLSS
4-31-29N-2E
Low Geology
Cahokia Alluvium, river valley
High Elevation
> 1235 feet above mean sea level
High Place
Charles Mound
High Quad Name
Shullsburg
High PLSS
4-13-29N-2E
High Geology
Silurian limestone hill
Area
613.63 square miles
Total Relief
645 feet
Percent Slope
4.25%