Lowest and Highest Points in Du Page County
Low elevation: <580 feet above mean sea level
Place: Des Plaines River
7.5' quadrangle name: Sag Bridge
PLSS: 3-16-37N-11E
Geology: River valley cut into Silurian/Devonian dolomite
High elevation: 820 feet above mean sea level
Place: Unnamed hilltop
7.5' quadrangle name: Lombard
PLSS: 3-28-40N-10E
Geology: Kenneyville Moraine
Area: 333.51 square miles
Total relief (approximate): 240 feet
Average percent slope: 0.88%
Updated 9/30/2009 JKH