Exposed only where drainage cuts slice through the peat, the structure at Kilmakill belongs to a class of ancient trackway known as a togher, a term used in Irish archaeology for roads built across bogland using timber, brushwood, or other available materials to create a passable surface over otherwise treacherous ground.

A peatland survey conducted in 2006 by Archaeological Development Services brought the togher to light, recording it at three separate points where it became visible in drain faces at the western edge of the bog. The structure runs on a broadly east-northeast to west-southwest orientation and stretches at least fifteen metres in the section surveyed. It is dated to after 1004 BC. The main body of the road is composed of six longitudinally laid planks, densely arranged with only five to ten centimetres between them, and sandwiched above and below by a fine layer of sand and gravel. One plank on the southern edge breaks from the general alignment, running northeast to southwest instead. At the westernmost point of exposure, the structure gave way to compacted stones and gravel rather than timber. A third sighting, located fifteen metres further northwest, was considerably narrower, consisting of a single roundwood piece roughly twelve centimetres in diameter alongside a small plank. The surrounding peat is a well-humified Sphagnum-rich deposit containing reed and Eriophorum, the kind of soft, wet bogland accumulation that, paradoxically, is often what preserves ancient organic material so well once it is sealed in place. The wood itself was recorded as being in a moderate state of preservation when observed in the drain faces, having survived buried between roughly thirty and seventy-three centimetres below the present field surface.