sentences:  Near Tahquitz at Joshua Tree, he did the first free ascent of "Left Ski Track" on Intersection Rock.Done in 1968, the climb is significant for its difficulty rating of 5.11, unusual for the time.Higgins began climbing in the High Sierra in California with the first ascent of the "East Buttress of Agassiz Needle, Temple Crag" with Couch; and the "North Face of Mt.