Sentinel Peak is a mountain located in the Glacier Peak Wilderness of Washington's North Cascades. The summit is part of the Ptarmigan Traverse. The mountain is situated on the crest of the Cascade Range, on the shared border of Snohomish County and Chelan County, also straddling the boundary between the Mount Baker-Snoqualmie National Forest and the Wenatchee National Forest. The South Cascade Glacier lies below its western slope, and the LeConte Glacier lies on the northeast slope. Its nearest higher peak is Spire Point, to the south-southwest.