Derryvree’s freshwater sediments challenge any simple image of MIS 3 Ireland as uniformly ice-covered or lifeless. They reveal a locally ice-free wetland between glacial advances, whereas Castlepook’s fauna records changing animal communities over a broader timespan. Together, these sites suggest that environmental opportunity may have varied sharply across both place and time. The possible tool-marked reindeer bone further raises the prospect of brief human activity without demonstrating settlement. This evidence cautions against island-wide conclusions from either site. How might future dating, stratigraphic, and zooarchaeological evidence clarify whether favourable local habitats also created repeatable opportunities for human visits during MIS 3?