Charles Mound[3] is a gentle, 1,235-foot (376 m) high hill located in Scales Mound Township, Jo Daviess County, Illinois, United States. It is 2 miles (3.2 km) northeast of the small town of Scales Mound, and 11 miles (18 km) northeast of Galena. Despite its name, Charles Mound is a naturally occurring, erosional feature and is not to be confused with the intentional mounds created by native cultures. It is the highest natural point in the state and is thus considered a state highpoint. It is the lowest state highpoint in the Midwestern region of the United States.
Geography
Sign at the summit of Charles Mound, June 2016Charles Mound, July 2014
Charles Mound is the highest natural point in Illinois. (The highest point is the Willis Tower, formerly known as the Sears Tower.) The top of the hill is about 0.25 miles (400 m) from the Wisconsin border. It is within the Driftless Area, a region of Illinois, Iowa, Minnesota, and Wisconsin that was not covered or ground down by the last continental glaciers. The hill itself is an erosional remnant, similar to that on which the original village site of Scales Mound was located. Shallow Elizabeth silt loam soil is on the summit and the surrounding area has deeper silty clay loam of the Lacrescent series.[4]
Geology
As mapped in the early 1960's by Mullens,[5] Charles Mound is an outlier and erosional remnant of Silurian Edgewood Dolomite overlying strata of the OrdovicianMaquoketa Formation. The Maquoketa Formation consists of dark-gray clayeysiltstone and siltydolomite that occurs in beds that are 2 in (5.1 cm) to 5 ft (1.5 m) thick. Within the Formation, layers of dark grayish-orange silty dolomite that are up to 2 in (5.1 cm) thick separate the beds of siltstone and silty dolomite. A prominent grayish-orange and grayish-yellow granular dolomite bed that ranges from 3 to 13 in (7.6 to 33.0 cm) in thickness, which contains abundant fossilbryozoa fragments, locally outcrops near Charles Mound. The Edgewood Dolomite is Unconformably overlying, and in erosional contact with, the Maquoketa Formation. The maximum thickness of Edgewood Dolomite preserved beneath Charles Mound is about 50 ft (15 m). The Edgewood Dolomite outcrops at the northwest and southeast ends of Charles Mound, and there presents as thin beds of grayish-orange and olive-gray medium-grained dolomite that contains light-gray chertnodules. The chert nodules are irregular in shape, 1 to 3 in (2.5 to 7.6 cm) thick and as much as 8 in (20 cm) long. Just southwest of Charles Mound is an abandoned prospectingshaft for lead-zincore.[5]
Settlement
Elijah Charles, one of the region's first permanent settlers, arrived in 1828 and settled at the base of the mound and the hill assumed his name.[6]
Access
Charles Mound is located on rolling farmland. The land owners, Jean and Wayne Wuebbels, allow public access on the first full weekends of the months of June, July, August, and September.[7]
^ abMullens,T. E., 1964. Geology of the Cuba City, New Diggings and Shullsburg quadrangles, Wisconsin and Illinois. U.S. Geological Survey Bulletin, no. 1123-H, p. 437-532.
