Towards the very end of the Ice Age the glaciers ended for a time at Fanore. At that time, Slieve Elva and Knockauns hill alone rose above the surrounding ice fields. The valleys facing Galway Bay had been widened considerably by glacial action, first when the ice moved south from Connemara and then when meltwater sought a runoff. When the ice finally retreated it also left moraines in valley bottoms and the characteristic drumlins (most of them on top of the shale and sandstone to the south). The Caher Valley was almost choked up by deposited sand and rocks and these also piled up against the western slopes of Slieve Elva. It was this protective layer of sediment that has made surface streams locally possible once more.