Sentinel Peak is an 8,266-foot mountain in Washington’s North Cascades, on the Cascade crest at the border of Snohomish and Chelan counties and between the Mount Baker-Snoqualmie and Wenatchee national forests. Part of the Ptarmigan Traverse, it is flanked by South Cascade Glacier on the west and LeConte Glacier on the northeast, giving it a strongly glaciated character. The mountain and its surrounding range were shaped over millions of years by tectonic activity, uplift, faulting, terrane accretion, volcanic processes, and repeated Pleistocene glaciation. In a marine west coast climate, Pacific weather brings heavy precipitation, snowy winters, and relatively clearer summer alpine conditions.