It appears in the official register of Irish monuments with the descriptor "indeterminate date", a phrase that sits quietly at the edge of the archaeological record, acknowledging that something is there while admitting that the usual tools of classification have not yet resolved what, exactly, it is or when it was built.

Rosgibbileen is a small townland in Mayo, a county whose landscape holds layers of settlement running from prehistoric field systems buried under blanket bog to post-medieval farmsteads abandoned during and after the Famine years of the 1840s. The classification of "house" in the archaeological record can cover a considerable range, from the stone footprint of a Neolithic structure to the roofless shell of a nineteenth-century dwelling, and the absence of a date here means the site has not yet been examined closely enough to place it within that span. Mayo has many such structures, particularly on marginal land where turf cutting, shifting land use, and depopulation left buildings without the documentary trail that might otherwise anchor them to a particular century or owner.