The Toce is a river in Piemont, Italy, which stretches the length of the Val d'Ossola from the Swiss border to Lake Maggiore into which it debouches near Fondotoce in the Commune of Verbania. The river is c. 76 kilometres in length and is formed in the upper Val Formazza by the confluence of a number of torrents in the plain of Riale. The source of one of these, the Gries, is situated on the Italian southern side of the Gries Pass; another forms beneath the Passo di San Giacomo, others flow from little Alpine lakes such as Lago Castel and Lago di Sabbione.