Long’s Peak, Rocky Mountain National Park, Colorado. A climber pauses for a view from the top of the Trough on the Keyhole Route on 14,256-foot Long’s Peak. This 15- mile long class 3 route provides the “easiest” access to the top of this peak as it ascends 5,000’ from the valley below. The route almost completely encircles the mountain as it spirals its way up to the flat granite summit. The eastern face of the mountain rises 2,500 feet above Chasm Lake in a sheer wall of perfect granite and presents one of the classic rock-climbing routes in North America.