If you’ve ever driven Cork Hill Road in Ogdensburg, you’ve passed through one of Sussex County’s oddest little landmarks without needing to slow down much. The Backwards Tunnel is a double-arched stone structure, 180 feet long, that has carried traffic, water, and local legend since 1871. Older generations knew it simply as “The Arch,” and kids grew up fishing in the Wallkill right beside it. One arch spans the road, the other channels the Wallkill River, and a sixty-foot embankment above once carried the rails of the New Jersey Midland Railway across the valley.

Why “Backwards”?

The nickname comes from a story first put in print during the borough’s 1976 bicentennial celebration: locals chuckled that the builders had put the tunnel in backwards, placing the wide opening over the water so only one wagon at a time could squeeze through on the road side. It’s a great yarn, but the 1871 engineers knew exactly what they were doing. A newspaper account from that September explains the wider river arch was designed to channel surplus water in times of flood. The name stuck anyway, and when Ogdensburg made the tunnel a borough historic site in 1991, “Backwards” Tunnel became official.

A Piece of Ogdensburg History

Built by contractor Simpson and architect Justin Arnold with a crew of fifty stone cutters, the tunnel was the heaviest piece of masonry on the entire Midland line. Its keystone was set in December 1871, and the last rail was spiked the following March. The railroad chose this spot because of a lucky leftover from the Ice Age, a glacial embankment across the Wallkill Valley that spared the line a ten-mile detour. The new rail service transformed the zinc mining operations at Sterling Hill and helped the village boom, eventually leading to Ogdensburg’s incorporation as a borough in 1914. Trains served the town for 87 years, until 1958, and the tunnel earned a spot on the National Register of Historic Places in 2005. It even weathered the “Great Flood” of August 2000, when two burst dams in Sparta raised the water to within a foot of the tunnel’s top.

Make a Day of It

The Sterling Hill Mining Museum is just up the road, and the Old Schoolhouse and Firehouse Museum rounds out a perfect afternoon of Ogdensburg time travel.

Visiting

Find the Backwards Tunnel on Cork Hill Road, just north of Passaic Avenue in Ogdensburg, NJ. It’s a public roadway, viewable any day.