Ski Technical Difficulty: We use a variation to the traditional Sierra Club system that was modified slightly to meet the needs of ski mountaineers by guide book author, John Moynier. Ski Class 1: Nearly flat terrain (less than 10 degress). Ski Class 2: Rolling terrain (up to 25 degrees) requiring intermediate skiing skills, but no mountaineering skills. Climbing skins recommended. Ski Class 3: Involves steep terrain (up to 35 degrees) requiring advanced skiing skills and avalanche hazard management. Besides climbing skins, avalanche transceiver, probe and shovel, we may often need to use ski crampons, an ice axe and a ski rope. Ski Class 4: Involves very steep terrain (35 to 45 degrees) requiring expert skiing skills and mountaineering skills including the use of ski crampons, ice axe, boot crampons and use of a rope. Ski Class 5: Extremely steep terrain (over 45 degrees) requiring a high degree of skills in all aspects of steep skiing and ski mountaineering.