http://librarian.i2p/get/17439170634712329780/7949404545163069226
Many districts contain mineral-rich rocks. Russia's most extensive region, the West Siberian Plain, is the most striking single relief feature of the country and quite possibly of the world. Covering an area well in excess of 1 million square miles (2.6 million square km), one-seventh of Russia's total area, it stretches about 1,200 miles (1,900 km) from the Urals to the Yenisey, and 1,500 miles (2,400 km) from the Arctic Ocean to the foothills of the Altai Mountains.