Stein's Pillar, 350 feet high and 120 feet wide, preserves evidence of this area's ancient volcanic past. Around forty-four million years ago, avalanches of hot ash, pumice, and volcanic dust flowing from local volcanic centers filled this ancient valley. A long period of erosion followed, and these flows are still visible in the layers of Stein's Pillar. Rain, wind, and frost slowly chiseled along cracks in the rocks, forming the valley and leaving Stein's Pillar as a beacon to travelers. Major Enoch Steen explored this area in the 1860's, and because his name was misspelled so often, the incorrect version became official. The pillar aided travelers and enticed geologists for many years.