The Caucasus Mountains extend approximately 1,200 km (750 mi) along the bor der between Russia in the north and Georgia and Azerbaijan in the south, from the Black Sea in the west to the Caspian Sea in the east . Forming a natural boundary between Europe and Asia, they cover 440,000 sq km (170,000 sq mi) and rise to a maximum elevation of 5,64 2 m (18,510 ft) in Mount Elbrus.
The mountain system was formed near the edge of the Alpine Geosyncline, abo ut 25 million years ago. Its more than 2,000 glaciers cover a total area of 2,000 sq km (772 sq mi). The Greater Caucasus, the ma in range, separates temperate and subtropical climate zones. The cold slopes facing the Black Sea may receive 2,540 mm (100 in) of precipitation annually; the Kura-Araks Lowland on the Caspian Sea is semidesert and receives only 200 to 400 mm (8 to 16 in). The Kura, Sulak, Terek, and Kuma rivers rise in the Caucasus Mountains and flow into the Caspian Sea; the Rioni and Inguri rivers rise i n the Caucasus and flow into the Black Sea; and the Kuban River rises in the Caucasus and flows into the Sea of Azov.
Mineral resources include petroleum, natural gas, manganese, copper, tungst en, and molybdenum. Livestock is raised on the heavily forested slopes. Wheat is grown in the northern piedmont and citrus fruits, cotton, and tea in the warmer valleys.