Sport climbing relies materially on the existence of routes equipped with bolts: vertical itineraries with anchors that allow climbers a safe ascent. Without bolting, sport climbing simply would not exist. In many countries, bolting is an altruistic individual activity that is usually neither organized nor regulated. Sport climbing bolting requires expensive hardware and sophisticated technical skills. However, equippers earn no money or prestige for this effort, which benefits many climbers. This paper develops a sociological approach to rock climbing bolting as a common-pool resource facing a deep crisis. In its early years, bolting was ruled by generalized reciprocity. The popularization of sport climbing quickly changed this framework. A small group of very active equippers has become net providers of public goods without compensation in economic or status terms.