Thompson Mill Bridge
The marker is mounted on the north end of the covered bridge across the Kaskaskia River. It is 3.2 miles northeast of Cowden. Turn east off of IL 128. Go 2.5 miles, and signs point the way to the bridge.
Illinois Department of Transportation and The Illinois State Historical Society
The road on which this bridge is located was once an important route between Springfield and Effingham. The bridge was completed in the autumn of 1868 at a cost of $2,500 and named for the owner of the first mill near here. It is the narrowest of all the covered bridges in Illinois, with a width of only 10 feet 7 inches. It is 11 feet 4 inches high and the siding stops before reaching the top cord to allow light to come in under the roof. The Howe Truss system, which the bridge uses, consists of panels in which two members cross one diagonal. The truss of this bridge is 105 feet long. The roof of the bridge protected the truss from weather.
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