Three Corner Rock is a short, easy hike to the site of a former fire lookout, which offers views of Washington volcanoes, the high peaks of the Columbia River Gorge, and Oregon's Mt. Hood and Mt. Jefferson.
From the Rock Creek Pass Trailhead, begin the short hike to Three Corner Rock by heading south on the Pacific Crest Trail from its crossing of Road CG 2090. After a steady 1.5-mile climb of roughly 600 feet, look for a large fallen sign marking the junction to Three Corner Rock. Shortly after, another older sign invites Pacific Crest Trail hikers to a reliable spring and the trail ends at a jeep road. Take a right and climb the remainder of the road to Three Corner Rock. Return the way you came.
Three Corner Rock is a great spot to see the sunset and strike up a conversation with thru-hikers on the PCT.