St. Clair River between Port Huron, Michigan and Sarnia, Ontario, Port Huron, Michigan. County/parish: St. Clair.
Added to the National Register of Historic Places October 15, 1970. NRIS 70000684.
3 contributing structures.
The St. Clair Tunnel is the name for two separate rail tunnels which were built under the St. Clair River between Sarnia, Ontario and Port Huron, Michigan. The original, opened in 1891 and used until it was replaced by a new larger tunnel in 1994, was the first full-size subaqueous tunnel built in North America. (By full-size it is meant that it allowed a railroad to run through it.) It is a National Historic Landmark of the United States, and has been designated a civil engineering landmark by both US and Canadian engineering bodies.
(read more...)National Park Service documentation: https://catalog.archives.gov/id/25340515