Bernese Alps through which the Rhône finds its way to Lake Geneva, to the Grimsel Pass or, depending on the definition, to the river Reuss (thus including the Uri Alps). The principal ridge, a chain that runs from west (Dent de Morcles) to east (Sidelhorn), whose highest peak is the Finsteraarhorn, forms the watershed between the cantons of Bern and Valais. Except for the westernmost part, it is also the watershed between the Rhine (North Sea) and the Rhône (Mediterranean Sea). This chain is not centered inside the range but lies close (10 to 15 km) to the Rhône on the south.
Puelo River course of the Ventisquero River. Traidor River rises in Hornopirén National Park. A large northern tributary of the Puelo, the Manso, has its sources in Mascardi Lake and other lakes and streams south-east of the Cerro Tronador, also in Argentina, and flows south-west through the Andes to unite with the Puelo a few kilometers west of the 72nd meridian. Puelo river's lower course is impeded in such a manner as to form three small lakes, called Superior, Inferior and the Tagua Tagua Lake. Puelo River The Puelo River has its origin in Lake Puelo in Argentine, and flows north-west through