Departing Wyoming, Underhill went on to California at the invitation of Sierra Club leader Francis P. Farquhar, for the purpose of teaching the most advanced techniques of roped climbing and belaying developed in the Alps. Underhill began by instructing a group of Sierra Club members in those techniques in the Minarets, practicing on the slopes of Mount Ritter and Banner Peak. After this introductory course, an advanced group led by Underhill and including Norman Clyde, Jules Eichorn, Lewis Clark, Bestor Robinson and Glen Dawson traveled south to the Palisades, the most rugged and alpine part of the Sierra Nevada. There, on August 13, 1931, this party completed the first ascent of the last unclimbed 14,000+ foot peak in California, which remained unnamed due to its remote location above the Palisade Glacier. After a challenging ascent to the summit, the climbers were caught in an intense lightning storm, and Eichorn barely escaped electrocution when a thunderbolt whizzed right by my ear. The mountain was named Thunderbolt Peak to commemorate that close call.