From Verbania Trobaso, Via al Cotonificio, you reach the cycle road on the left side of the San Bernardino river, go up to Unchio and the Oratory of Motto di Unchio, then through a peat bog and Pian di Les, you reach Cossogno (crossroads P00).
Datos de la ruta de los colaboradores de OpenStreetMap, con licencia ODbL.