A field survey identified 44 toghers, or togher-like structures, within the single townland of Cooleeny, a density that speaks to sustained, purposeful movement across what would have been treacherous, waterlogged ground. A togher is a timber road laid across bogland, built to allow people and animals to cross terrain that would otherwise have been impassable, and the examples at Cooleeny show considerable variety in their construction despite sharing the same challenging environment.

Most of the trackways were built using a combination of brushwood and roundwood laid together, though builders clearly adapted to available materials: six were constructed from roundwood alone, eight from brushwood alone, and one unusually incorporated brushwood and gravel together. Across seventeen of the toghers, analysis identified the wood species used, and the range is striking: alder, ash, birch, blackthorn, hazel, mountain ash, and willow all appear, suggesting that builders were drawing on whatever the local woodland and scrub could supply rather than selecting a preferred timber. Two of the trackways have been directly dated by radiocarbon analysis, both falling within the Iron Age. One returned a date range of 388 to 207 BC, the other 372 to 192 BC, placing their construction in a period when Irish communities were clearly investing considerable effort in making the bog navigable. Whether these routes served farming, trade, or ritual movement through the landscape is not recorded, but 44 crossings within a single townland implies that Derryville Bog was not a barrier to be avoided so much as a space that needed to be threaded through, repeatedly and deliberately.