mountains in northeastern France. Length, 160 km. Width, 40-50 km. Principal summit, Ballon de Guebwiller (1,423 m). The eastern slope of the Vosges descends sharply to the Upper Rhine Lowland, whereas the western slope is gently sloping. The Vosges form the western section of the Hercynian massif, raised in the form of an arch, the keystone of which foundered, forming the graben of the Upper Rhine Lowland. The eastern part of the arch forms the Black Forest Mountains. In the south the Vosges are com-posed of crystalline rocks and have gently sloping summits with traces of Anthropogenic glaciation; in the north are sandstone plateaus with cuesta-like bluffs. Up to an elevation of 1,200 m the mountains are covered with beech, fir, and spruce forests. Up to an elevation of 800 m there is agriculture (in the valleys), and higher up there is forestry.