Altay - geologically complex mountain system in central Asia; largely in the Altay Republic in Russia, and in Kazakhstan, but also extending into Western Mongolia and Northern China. In the north-east the Kuznetsk Ala-Tau and the Salair Ridge adjoin the Altay and enclose the Kuznetsk Basin.
The highest sections of the Russian Altay are the Katun, the Chuya, and the Sailyugem ranges. The highest peak in the Russian Altay, Belukha (14,783 ft/4,506 m), is in the Katun range.
Meltwater from extensive glaciers feeds many rivers; the Ob and the Irtysh rise in the Altay. Lake Teletskoye, with an area of 90 sq mi (233 sq km), is the largest of the Altay's more than 3,000 lakes.
Rich deposits of gold, silver, mercury, iron, lead, zinc, and copper are found in the mountains, especially in Eastern Kazakhstan.
Located in the centre of the great Asian landmass, the Altay have a continental climate with a wide annual temperature range and receive c.40 in. (101.6 cm) of precipitation annually. Bears, martens, musk deer, and mountain goats inhabit the mountains.
The first Russians entered the area in the 17th century and mined silver. In the late 19th century, piedmont agriculture replaced mining as the main occupation.
After the Soviet take-over in the early 20th century, the area became both an important farming and mining region.
Oskemen and Leningor are principal mining and industrial centres.