Altai Mountains (Chin. Ghin-Shan, Gold Mountains), one of the greatest mountain systems of Asia, stretching 5,000 miles from long. 85° E. to the Sea of Okhotsk, and separating the Russian Empire from that of China. The collateral branches cover a breadth in some parts of 800 to 900 miles. The average height does not exceed 5,000 feet, but the Russian Altai reaches 12,000. The mountains consist of rounded granite masses with no peaks or jagged crests. The rivers Obi, Irtish, and Yenesei have their sources in these ranges, the mineral wealth of which is probably enormous. Gold, silver, copper, iron, lead, and various kinds of gems abound in them. Forests of hardy trees clothe the lower slopes, and the wild sheep has its home there. The Altai proper is the portion of the system within the province of Tomsk, Siberia. The main ridge is the Sailughem, which as it extends south-west is known as the West Sajan. The fertile valleys to the south are being rapidly colonised; the chief town is Barnaul.