- Buckner Mountain (sometimes called Mount Buckner) is a tall peak in the North Cascades of Washington state and in the Stephen Mather Wilderness of North Cascades National Park. At 9,114 feet (2,778 m) in elevation it is the highest in Skagit County and one of about ten of Washington’s non-volcanic peaks above 9,000 feet high. It is ranked as the 14th highest peak in the state, and the third highest peak in North Cascades National Park.