Lowest and Highest Points in Marshall County
Low elevation: <465 feet above mean sea level
Place: Illinois River
7.5' quadrangle name: Chillicothe
PLSS: 3-32-29N-3W
Geology: Cahokia Alluvium in river valley
High elevation: >895 feet above mean sea level
Place: Unnamed hilltop
7.5' quadrangle name: La Prairie Center
PLSS: 4-32-13N-8E
Geology: Providence Moraine
Area: 395.01 square miles
Total relief (approximate): 430 feet
Average percent slope: 1.47%
Updated 9/30/2009 JKH