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.
Swiss Alps on the shores of Lake Geneva to Rorschach on the shores of Lake Constance, passing close to the cities of Thun and Lucerne. The not well defined regions in Switzerland that lie on the margin of the Alps, especially those on the north side, are called the "Swiss Prealps" ("Préalpes" in French, "Voralpen" in German, "Prealpi" in Italian). The Swiss Prealps are mainly made of limestone and they generally do not exceed . The Alpine cantons (from highest to lowest) are Valais, Bern, Graubünden, Uri, Glarus, Ticino, St. Gallen, Vaud, Obwalden, Nidwalden, Schwyz, Appenzell Innerrhoden, Appenzell Ausserrhoden, Fribourg, Lucerne and