Western Alps, a physiographic section of the European continent, are the western half of the Alps located west of a convenient division made along an imaginary line drawn from Lake Constance through the Splugen Pass to Lake Como. The central part of the Western Alps is composed of the crystalline rocky massifs of Saint Gothard and Mont Blanc. - AsNotedIn

Subdivisions

Ligurian Alps (from Savona to Colle di Tenda)
Maritime Alps (from Colle di Tenda to Colle della Maddalena)
Cottian Alps (from Colle de la Maddalena to Montgenevre Pass)
Dauphine Alps (from Col du Mont Genevre to Col du Mont Cenis)
Graian Alps (from Col du Mont Cenis to the Col Ferret)
Chablais Alps (from Lake Geneva to the Col des Montets)
Pennine Alps (from Col Ferret to the Simplon Pass)
Lepontine Alps (from Simplon Pass to Splugen Pass)
Bernese Alps (north of the Rhone to the Grimsel Pass)
Urner Alps (from Grimsel Pass to the Reuss)
Glarus Alps (north-east of Oberalp Pass)
Appenzell Alps (north of Sargans).