It is a togher, the Irish term for a timber trackway laid across wet or marshy terrain, and this particular example is modest in scale but precise in its construction: one metre wide and just fourteen centimetres deep, running east to west through the bog.

The structure follows a method of building that was used across Ireland for thousands of years. Long pieces of roundwood were laid lengthways along the direction of travel, with larger transverse timbers placed beneath to support them, and hazel brushwood worked in among the longitudinal planking to fill gaps and add stability. Hazel was a practical choice, its flexible, relatively slender stems well suited to weaving into the body of a trackway where rigidity alone would not hold. The classification as a class 3 togher reflects a typology developed through wetland archaeological research, grouping trackways by their structural complexity and the materials used. This one sits in the middle range, more considered than a simple bundle of branches thrown across a puddle, but without the elaborate carpentry of the great prehistoric roads such as those found at Corlea, also in County Longford, where massive oak planks were used to construct a trackway dating to around 148 BC. The Derryoghil togher represents the more everyday engineering of bog travel, practical and unshowy, built to solve an immediate problem of movement across difficult ground.