Big Four Mountain is a prominent 6,160-foot peak in Washington’s Cascade Range, widely recognized along the Mountain Loop Highway near Monte Cristo. It is best known for the snow and avalanche debris that accumulate on its north side, where shaded snowfields can last year round and summer meltwater carves the Big Four Ice Caves. These caves change constantly and are dangerously unstable; deaths occurred there in 1998, 2010, and 2015, and the snowfield is closed to visitors. The mountain also holds the Cascades’ lowest-elevation permanent ice, has ties to the Rucker Brothers and the Big Four Inn, and reflects the region’s glacial and tectonic history.