Derryvree’s freshwater silts are especially compelling because they show a locally ice-free wetland between glacial advances, while Castlepook suggests that animals, and perhaps people, could have moved through similarly unstable landscapes. Yet neither archive offers a single moment in time: the wetland date is a broad calibrated bracket, and a possible cut mark on reindeer bone cannot demonstrate settlement. This contrast highlights how environmental evidence may be firmer than conclusions about human presence. How should researchers weigh Derryvree’s ecological record against Castlepook’s complex faunal evidence when assessing whether Late Pleistocene Ireland supported occasional human visits or only transient animal movement?