These are toghers, a word from the Irish tóchar, referring to causeways built across wet or boggy ground by weaving together branches, poles, and other woody material into a firm enough surface to walk or carry loads across. What makes the concentration at Cooleeny townland unusual is sheer number. A single field survey, conducted by Gowen in 1999, identified them across this one stretch of bog, each one a separate engineering decision made by people navigating the same difficult ground.

The toghers vary considerably in their construction. Most combine brushwood, the smaller branchy material cut from shrubs and trees, with roundwood, which refers to whole small poles or rods rather than split timber. Six were built from roundwood alone, eight from brushwood alone, and one incorporated gravel alongside brushwood, a notably different approach. Wood species were identified in seventeen of the toghers, and the variety is striking: alder, ash, birch, blackthorn, hazel, mountain ash, and willow all appear, suggesting builders were selecting from whatever grew locally rather than following a single prescribed method. Two of the toghers have been dated through scientific analysis, both falling within the Iron Age. The calibrated date ranges, 388 to 207 BC and 372 to 192 BC, place their construction somewhere in the centuries before the Christian era, when the bog was apparently crossed with enough regularity to justify repeated, effortful construction across the soft ground.