It was there before the surveyors came, and it was there after they left, and yet they did not record it. That omission is itself a small puzzle, because cairns of this kind were typically placed precisely where boundaries needed to be made legible in the landscape, at the edges of territories, parishes, or townlands, marking the line where one jurisdiction ended and another began.

The cairn at Coppanaghmore is described as probably a boundary cairn, which places it within a tradition of landscape markers used long before the administrative county lines that now bisect this part of Ireland were formalised. Boundary cairns served a practical purpose, visible from a distance, unambiguous to anyone walking a frontier, and requiring no literacy or document to be understood. That this one sits precisely on the Cavan and Leitrim county boundary lends the classification a certain logic, even if the cairn's original purpose and age remain unconfirmed. It has not been formally inspected, so questions about its construction, scale, and precise condition are still open.