The Mystery Wall Beneath the Susquehanna

In August 1911, several Pennsylvania newspapers carried an unusual story from the lower Susquehanna. A local man claimed to have found the remains of a strange stone wall running across the river between Drumore Township’s Fishing Creek and Benton Station. Benton Station was once accessible via Benton Hollow Road, now Wildlife Preserve Road, within what is today Lancaster Conservancy’s Ferncliff Wildlife & Wildflower Preserve.

Approximate location of the mystery wall.

The discovery was attributed to Joseph A. Trimble, a native of the area, who reportedly came upon the feature while building a fish dam near the southern Lancaster County shore. The reported wall was said to extend across the Susquehanna toward the York County side.

According to the newspaper accounts, the structure was not a loose scatter of rocks but a distinct line of stone visible beneath the water. Reports described it as a narrow wall, about eighteen inches wide, built on the river’s bedrock. It supposedly crossed from the Lancaster side, touched an island in midstream, and continued toward York County.

What made the story especially intriguing to reporters was the material. The wall was said to be composed of heavy black flint rock, with many of the blocks measuring roughly nine by eighteen inches. Trimble reportedly tried to use some of the stones in his own fish dam but found them too heavy to handle. The newspapers also claimed that the stone did not resemble anything known locally and suggested it must have been brought in from far away.

The shape of the stones added another layer to the mystery. Reporters described them as dressed or cut, suggesting they had been deliberately shaped rather than broken naturally. One account even mentioned the discovery of a large rectangular stone lying nearby on the river bottom, resembling a quarried building stone rather than a random boulder. To early twentieth-century readers, this made the find seem all the more remarkable.

From the beginning, the reports framed the structure as ancient and possibly prehistoric. Since no one in the area seemed to remember such a wall being built, and no local records were said to mention it, newspaper writers quickly dismissed the idea that it was a relatively recent construction. Some articles even suggested it had been built by an unknown people who lived in the region before the Native communities known to history. Others suggested it may have been part of some long-vanished canal or irrigation system.

A small group of men, including Trimble and visitors from Harrisburg, reportedly went to examine the site together. At least one newspaper reported that the water was remarkably clear that day, allowing the structure’s outlines to be seen clearly from above. Further investigation was promised once the river dropped even lower.

But that investigation never seems to have happened, and it is unlikely to happen today. Fifteen years after the discovery, the completion of Conowingo Dam transformed the lower Susquehanna, backing up the river into a vast 9,000-acre reservoir. If the wall truly existed where the 1911 accounts placed it, then it now lies deep beneath dark water and generations of accumulated silt.

So, what might it have been?

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Resources

• The Star-Independent Mon, Aug 07, 1911
• Lancaster Daily Intelligencer Mon, Aug 07, 1911
• The Patriot-News Tue, Aug 08, 1911
• Altoona Times Fri, Aug 11, 1911
• The Inquirer Sat, Aug 12, 1911
• The Record Thu, Aug 17, 1911
• The Oxford Press Aug 17, 1911
• The Ephrata Review Fri, Aug 18, 1911
• Lancaster County Train Stations of the Past