This study faces the commons as a negotiating area of fiscal nature, relating it to the discountinuous historical process of formation of forest and the use of the high lands. The historical production of a political border between the Savoy Piedmont and the territories of the Republic of Genoa has let us reconstruct the fragmentary traces of a long process of negotiation about the use and the jurisdiction of woods and pasture of an alpine territory, located between the high valleys Roya, Tanarello and Arroscia. Between the 15th and 18th century the commons take shape as rights of local use, negotiated in different forms of «collettazione» (raising money/fiscality). At the beginning it is linked to the alpine communities, later it is applied to the local management of greens production and finally transposed to the dairy production of mountain pasture stations. The case-studies analysed in the second part allow us to show how the commons emerge in the steady adaptation of the forms of management of environmental practices in the use of alpine resources.