Paul Bunyans Stump was first climbed on August 2, 1931 by William Degenhardt and Herbert Strandberg of the Seattle Mountaineers. They called it What's the Matterhorn. The approach is via the Pyramid Lake Trail, starting near Diablo Dam on the North Cascades Highway. From the lake, it's route-finding up Pyramid Arm and to Colonial Glacier. The standard route is a scramble on the southwest slope after accessing the Colonial Glacier.