Stillaguamish Peak is a 5,720-foot summit near the western edge of Washington’s North Cascades, rising sharply above the Stillaguamish River valley within Mount Baker-Snoqualmie National Forest. Close to Monte Cristo and Barlow Pass, it stands in a marine west coast climate where Pacific storms bring heavy rain, dense winter snow, and significant avalanche danger, while clearer summer weather usually makes July through September the best time for viewing or climbing. The peak also reflects the deeper geologic history of the North Cascades, where terrane accretion, uplift, faulting, volcanism, and repeated Pleistocene glaciation created the region’s rugged ridges, steep relief, and U-shaped valleys.