The Paw Paw Tunnel in Allegany County, Maryland, is one of the most remarkable engineering accomplishments along the C&O Canal. Designed to eliminate the need for six additional miles of canal along a stretch of the Potomac River, the tunnel became one of the canal’s most significant construction challenges.

Work on the Paw Paw Tunnel began in 1836 and was expected to take just two years. Instead, due to labor disputes, fights amongst workers, funding shortages, construction delays, and frequent work stoppages, the project ended up taking 14 years. When the tunnel finally opened in October 1850, the C&O Canal Company had been pushed to the edge of bankruptcy. The finished structure measures 0.6 miles long and was constructed with almost 6 million bricks.

After its completion, the tunnel remained a site of conflict. Boatmen were in constant fights with one another over right of passage through the tunnel. Downstream traffic was supposed to yield, but many refused, leading to heated disputes. Some boatmen even resorted to lighting fires to “smoke out” other boats inside the narrow passage.

Visiting the Paw Paw Tunnel (mile 155.2) in winter is a little different. To protect the interior brickwork from freeze–thaw damage and harsh winter winds, park staff board up the south end each year. The tunnel remains open to visitors, who can enter through a designated “doorway” in the temporary barrier.

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