From left to right: Mt. Silex, Peak 9, and the Guardian. Lake Silex is set down below all 3 of these peaks. One reason why there are still icebergs in the lake. Technical climbs can be found on all 3 of these peaks. Peak 9 is one of the most difficult mountains in Colorado with a technical ascent necessary (all 5th class) to summit. August 7, 2005. Copyright attm.