As the edge of the continental ice sheet moved from the north down this valley, it blocked rivers and formed glacial lakes. As the ice gradually melted, a lake rose here behind the receding ice dam and extended up Kootenai valley into Canada. Until the ice disappeared about 10,000 years ago, this lake drained through the valley to the south. Then Kootenai river cut down the lake bottom, exposing the small tree-covered granite hill in the valley before you. Lakes Coeur d'Alene and Pend d'Oreille to the south are remnants of this glacial action.