Rating Ski Descents – D System by Lou Dawson July 7, 2016 by Lou Dawson July 7, 2016 Rating backcountry skiing routes, danger, length, difficulty for ski mountaineering, D System and more.
Backcountry Skiing Rating System by Lou Dawson October 17, 2005 by Lou Dawson October 17, 2005 Backcountry Skiing and ski touring Rating System, D System gets many changes and edits.