At Pieve di Bono it enters the lower valleys of Giudicarie, receiving the waters of the torrente Adanà.

Further south it flows through the Lago d'Idro near Baitoni before running down into Lombardy and the Province of Brescia.

Here it enters the pianura padana, and flows south through Gavardo, Calcinato, Montichiari, Carpenedolo and Acquafredda, enters the Province of Mantua at Asola, before flowing into the Oglio on its left bank in the valley of Acquanegra sul Chiese.

Like its twin the Sarca, the river is born of the glaciers of the Parco naturale provinciale dell'Adamello-Brenta and its waters are intensively used for the production of hydro-electricity.

Within the highly restricted area of its drainage basin above Lago d’Idro there are at least four artificial lakes and three hydro-electric power stations.