Glacier Peak, or Dakobed, is a remote stratovolcano in Washington’s North Cascades and the state’s fourth-highest peak. Built mainly of viscous dacite, it is among Washington’s most active volcanoes and, with Mount St. Helens, one of only two to produce major explosive eruptions in the last 15,000 years. Its largest known eruptive episode about 13,100 years ago spread ash across the Pacific Northwest and sent lahars to Puget Sound, leaving deposits that still shape downstream valleys. Sacred to the Sauk-Suiattle people and central to a major wilderness-era conservation fight, it remains heavily glaciated, hazardous, and sparsely monitored despite its high threat.