(CN-Green Valley Rd.) under CN RR SW of Clinton, Tunbridge Townhip, DeWitt County, IL. IL54 SW 3.8 miles from jct with US51 on the W. side of Clinton, N. on Green Valley Rd. (5000E) 250’ to the tunnel. (N40 07.309 W89 02.871) Photo by Jack & June Schmidt 9-4-19.