“Mile High” Idyllwild (altitude 1.6 km) and Tahquitz Rock, often called Lily Rock, have received world-wide recognition from rock climbers since the 1930s. In 1947, a “difficulty of climb” scale, based on Tahquitz Rock, was established. After the ascent of Half Dome in 1957, the Sierra Club tweaked the values and the ratings became known[…]