It came to light around 1980 during commercial peat-milling at Knappoge, when machinery broke through the surface and revealed a gravel trackway lying about a metre below ground. The bog had sealed it so effectively that it remained largely intact, a working road of the early medieval period preserved in near-darkness under layers of compressed peat.

When a 190-metre section of the road was excavated in 1988, its construction turned out to be considerably more sophisticated than its rural setting might suggest. The surface consisted of large pebbles set into a bed of fine gravel and sand, but below that lay a layer of coarser gravel reinforced with oak transverses, essentially oak timbers laid crossways to stabilise the foundation and prevent the whole structure from sinking into the soft ground. Beneath even that, excavators found occasional pockets of worked hazel, birch brushwood, and twigs, organic material that had been deliberately placed to provide additional support. The overall trackway ran at least 600 metres, orientated roughly north-north-east to south-south-west. Radiocarbon dating placed its construction between AD 669 and 777, situating it firmly in the early Christian period in Ireland, a time when roads of this kind, known from bog contexts across the country, would have served as essential routes through otherwise impassable wetland terrain.