This paper studies the legal institutions set up by communities in the Italian Alps in the 13th – 19th century to manage their common pastures and forests. Over time, private-order institutions in the form of charters replaced informal arrangements sustained by the long-run interaction among villagers. Although costly to run, the charters accomplished several tasks that increased resource use efficiency. We present an empirical analysis of institutional choice of about two hundred communities and show that relative efficiency was an important factor in the selection of a governance regime.