Mount Persis is a prominent 5,464-foot peak in Washington’s Cascade Range near Index, within the Mount Baker-Snoqualmie National Forest. Rising sharply above the valley, it sends runoff into tributaries of the Skykomish River and is especially notable for climbing 4,160 feet above Anderson Creek in only 0.8 mile. The summit was named for Persis Gunn, linking it to the early settlement history of Index and the Gunn family, including founder Amos Gunn. Beyond its dramatic profile, the mountain is geologically important because its volcanic rocks are considered among the earliest expressions of volcanism in Washington’s Cascade Range. Its marine west coast climate brings heavy winter rain, snowfall, and avalanche danger.