Yenisey (or Yenisei) River, a principal river of Russia. From its headwaters near the Mongolian border, the Yenisey flows northward nearly 2,100 miles (3,400 km) and empties into the Kara Sea. This great Siberian river cuts through mountains, taiga (dense coniferous forests), and tundra (a treeless Arctic zone). With its many tributaries, including the Angara, Lower Tunguska, and Stony Tunguska, the Yenisey drains a basin of some 1,000,000 square miles (2,600,000 km2). It has the largest flow of any Russian river.

The Yenisey is navigable from three to six months of the year, when the river is free of ice. River craft carry mainly timber and minerals produced in the area. Near Krasnoyarsk, the largest city on the Yenisey, is Krasnoyarsk Dam, one of the most powerful hydroelectric installations in the world. There are other large dams along the Yenisey and its tributaries.