Low Elevation
< 630 feet above mean sea level
Low Place
Somonauk Creek
Low Quad Name
Somonauk
Low PLSS
3-34-37N-5E
Low Geology
Cahokia Alluvium, river valley
High Elevation
> 940 feet above mean sea level
High Place
unnamed hilltop
High Quad Name
Genoa
High PLSS
3-10-41N-5E
High Geology
Elburn Moraine complex
Area
629.22 square miles
Total Relief
310 feet
Percent Slope
0.74%