Castle Rock is an mountain summit located on the shared border of Glacier Peak Wilderness and Lake Chelan National Recreation Area in the North Cascades of Washington state. The mountain is situated above the western shore of Lake Chelan in Chelan County, on land managed by Wenatchee National Forest. Its nearest higher peak is Flora Mountain, to the south. Precipitation runoff from the peak drains into Lake Chelan via Castle Creek, Canyon Creek, and Bridal Veil Creek.