On Old Pearl Rd between Pearl & Nebo
+39.44601, -90.6635839°26'46" N, 90°39'49" W
The original culvert was built in the 1860s as the railroad built west toward the Mississippi River. Due to a large grade and the operational issues it brought, the line was realigned to the south in 1889, resulting in the southernmost culvert's construction. The culverts are shared between a small, intermittent stream and Old Pearl Road/Township Road 461, and are about 230 feet (70 meters) apart.
In between the embankments is the Twin Culverts Cave that is part of the Twin Culverts Cave Nature Preserve. The cave is located about 15 feet away from the road on the west side. About 1000 feet is accessible by humans; however, the cave is closed to protect it from vandalism and to protect a species of Gray Bat that lives in the cave between September and October. Cave may be opened by request.
- November 12, 2019: Added by Nathan Hopper