What makes the arrangement quietly peculiar is not just its age but its material inconsistency. The three northern stones are rounded granite boulders, stepping down in height from north to south at 1.8m, 1.2m, and 0.7m. The three southern stones follow the same descending pattern, at 1.6m, 0.7m, and 0.5m, but are rectangular slabs of schist, a completely different rock type. The overall alignment runs north to south across 16 metres, and a possible seventh stone sits roughly 0.6 metres further to the north, though its status remains uncertain. Whether the two different materials reflect different phases of construction, different sources of available stone, or something else entirely, is not resolved.

A stone row is a prehistoric monument type found across Ireland and Atlantic Europe, generally understood to date from the Bronze Age, though precise dating at individual sites is rarely straightforward. At Derryinver the row does not stand in isolation. The Tulach carries a wider complex of early monuments, including a pre-bog enclosure roughly 100 metres to the north-east, an unclassified stone structure about 35 metres to the south-west, and a series of pre-bog field walls in the vicinity. The term pre-bog simply means that these features were already in place before the blanket bog that now covers much of this landscape began to form, suggesting considerable antiquity. The site was noted by Killanin as early as 1954, and was subsequently recorded by Ó Nualláin in 1988 and by Gibbons and Higgins in the same year, placing it within a broader survey of the region's megalithic monuments.