Cévennes (sāvĕnˈ) [key], mountain range, S France, bordering the Massif Central on the southeast. The Cévennes proper occupy the central section of a mountainous arc (average height 3,000 ft/910 m), swinging generally NE from the Montagne Noire (NE of Toulouse) to Mont Pilat (SW of Lyons). Between the Cévennes proper and the Montagne Noire are the Causses—barren limestone plateaus intersected by deep chasms and ravines. The Loire, Allier, Lot, Tarn, Aveyron, Hérault, Gard, and Ardèche rivers all radiate from the Cévennes or the Causses. Mont Lozère (5,584 ft/1,702 m) is the highest peak of the Cévennes proper; Mont Mézenc rises to 5,753 ft (1,754 m). The cultivation of silkworms and the manufacture of silk were characteristic of the area, but the silk industry has greatly declined. Heavy industry in Alès is on the decline. Intensive sheep raising in the interior has worsened erosion, but a reforestation program has been started.