the first ascent of the Nutcracker in Yosemite Valley using exclusively these wedges. He wrote about this six-pitch climb and others in Summit magazine and the American Alpine Journal but without much obvious immediate influence. Within several years, another well-known Yosemite climber, Yvon Chouinard, began to commercially manufacture metal chocks, or nuts, in California. An important milestone occurred with the 1972 Chouinard Equipment Catalog, which included two articles on environmental concerns and climbing gear. One was written by Chouinard and Tom Frost; another was by Doug Robinson titled "The Whole Natural Art of Protection". Around this time, Bill Forrest also produced a somewhat less successful range of passive chocks, more successful were his experiments with camming which went on to become the first Lowe Alpine System active camming devices (sometimes jokingly called "crack jumars"). Many other prominent climbers of the era, including John Stannard at the Shawangunks in New York, were influential participants in this early 1970s movement. As a result, climbers en masse rapidly adopted the technique, pitons quickly fell from favor, and the switch to "clean climbing" constituted a landmark change in the sport of rock climbing. Conditions today Piton scars from an earlier era are still widely visible. Today, on a relative handful of long-established climbing routes in a few places, these old scars enable the use of clean hardware. Such hardware would have been less useful on these particular routes before the rock was altered. Some routes which had been only ascendable on aid "go free" today for the same reason: there are in some places cracks smaller than fingertips which can now be climbed without aid because piton scars provide holds which didn't previously exist. Values and regulation Most rock climbing, both long before and immediately after the development of "clean climbing", would now be classified as traditional climbing in which protection was installed and removed by each successive party on a given route. However, the term "trad climbing" only arose later, to describe that which is not sport climbing, a comparatively recent activity in which all protective gear is permanently and abundantly fixed on certain routes. Fixed gear certainly existed in 1970 as it does now. Some contemporary routes, like a number of long, limestone climbs in the Bow Valley, Alberta, are notable for fixed bolts at belay stances and for protection at relatively wide intervals, and thus a kind of hybrid of trad