and sport is possible—if supplementary gear can be placed. Perhaps the most extreme example of acceptable non-"clean climbing" is the many via ferrata mountaineering routes, of primarily the Alps. A relatively small number of climbers believe in varying degrees that fixed gear should never be placed on any route in order to preserve the rock and its inherent challenges. This long-standing cultural question of doctrine is largely separate from issues that gave rise to the term "clean climbing." Some climbing areas, notably some of the national parks of the United States, have de jure regulations about whether, when and how hammer activity may be employed. For example, drilling is not banned in Yosemite, but power drills are. Other areas have de facto local ethics prohibiting certain activity. For example, bolting is not banned in Pinnacles National Park, but the local climbing community does not tolerate rap-bolting — bottom-up route development is expected. References Peter Livesey Climber and Hillwalker magazine article External article on English history: Types of climbing