A field survey of Cooleeny townland identified 44 toghers, the Irish term for a bog road or trackway, laid down to allow people and perhaps livestock to cross terrain that would otherwise have been impassable. What makes this concentration remarkable is not just the number but the variety of construction methods on display across a single bog landscape.

A togher is essentially a causeway built from timber and other organic material laid across waterlogged ground, and the examples at Cooleeny show considerable ingenuity in their making. Most were built from a combination of brushwood and roundwood, though six used roundwood alone, eight relied entirely on brushwood, and one unusual example incorporated brushwood and gravel. Two of the toghers have been radiocarbon dated, placing their construction firmly in the Iron Age: one yielded a date range of 388 to 207 BC, the other of 372 to 192 BC. Wood species were identified in seventeen of the toghers, and the range is striking: alder, ash, birch, blackthorn, hazel, mountain ash, and willow were all used, suggesting that builders were working opportunistically with whatever timber was locally available rather than selecting a single preferred material. The presence of blackthorn in particular points to the use of scrubby, tangled growth that might otherwise seem unsuitable for construction. Collectively, the toghers represent a sustained, repeated effort by Iron Age communities to negotiate the bog on their own terms, generation after generation laying fresh timber into the same uncertain ground.