repeatedly scoured the landscape leaving deposits of rock debris. The last glacial retreat in the Alpine Lakes area began about 14,000 years ago and was north of the Canada–US border by 10,000 years ago. The “U”-shaped cross section of the river valleys are a result of that recent glaciation. Uplift and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the Alpine Lakes Wilderness area. See also List of peaks of the Alpine Lakes Wilderness Geology of the Pacific Northwest References External links Fortune Peak weather: National Weather Service Alpine Lakes Wilderness (Okanogan-Wenatchee National Forest) U.S. Forest Service Mountains of Chelan County, Washington Mountains of Kittitas County, Washington Mountains of Washington (state) Wenatchee National Forest Cascade Range North American 2000 m summits