Yenisey

Yenisey, river, central Siberian Russia, 4,090 km (2,540 mi) long. It is formed in the Sayan Mountains by the union of the Biy-Khem (Greater Yenisey) and the Ka-Khem (Little Yenisey), in the eastern part of Tuva, and flows generally north. The Yenisey flows swiftly through a deep gorge in the Sayan Mountains. Less turbulent just south of Krasnoyarsk, it traverses successively a grain-growing region; the taiga, a region of coniferous forests; and the tundra. It empties into Yenisey Gulf, an arm of the Kara Sea; its estuary is 160 km (100 mi) long and has a maximum width of 64 km (40 mi). The Yenisey drains more than 2.6 million sq km (1 million sq mi). Although navigable for about 2900 km (about 1800 mi), it is usually frozen from November to May. The chief tributaries of the Yenisey are the Kan, the Angara, the Kureyka, the Abakan, and the Upper Tunguska, Stony Tunguska (Podkamennaya Tunguska), and Lower Tunguska (Nizhnyaya Tunguska) rivers.