These are toghers, a type of trackway built across boggy or waterlogged ground by laying timber directly onto the soft surface, and the concentration of them within a single townland, Cooleeny, is remarkable. Rather than a single route, what survives here is something closer to a network, suggesting repeated, purposeful movement across terrain that would otherwise have been impassable.

A field survey carried out in 1999 recorded the full extent of the Cooleeny toghers and examined how they were built. Most combined brushwood, the smaller flexible branches used to create a matted base, with roundwood, the straight lengths of timber laid across it for stability. Six toghers used roundwood alone, eight relied entirely on brushwood, and one incorporated gravel alongside the brushwood for additional firmness underfoot. Seventeen of the toghers yielded identifiable wood species, and the variety is striking: alder, ash, birch, blackthorn, hazel, mountain ash, and willow all appear, suggesting that builders were drawing on whatever suitable timber grew locally rather than selecting any single preferred material. Two of the toghers have been radiocarbon dated. Both returned Iron Age results, one to 388 to 207 BC and another to 372 to 192 BC, placing their construction somewhere in the middle centuries of the first millennium before the common era, during a period when Irish communities were already well practised in the engineering of bog roads. The bog itself has acted as an accidental archive, its waterlogged, oxygen-poor conditions slowing the decay of organic material that would long since have vanished in drier ground.