Lowest and Highest Points in McLean County
Low elevation: <600 feet above mean sea level
Place: Sugar Creek
7.5' quadrangle name: Armington
PLSS: 3-31-22N-1W
Geology: Cahokia Alluvium and till in river valley
High elevation: >950 feet above mean sea level
Place: Unnamed hilltop
7.5' quadrangle name: Saybrook
PLSS: 2-6-23N-6E
Geology: Fletcher / Eureka / Normal Moraine complex
Area: 1,174.05 square miles
Total relief (approximate): 350 feet
Average percent slope: 0.75%
Updated 10/1/2009 JKH