River, northeastern Siberia , eastern Russia.
Rising in the Kolyma Mountains and emptying in the East Siberian Sea, it is 1,323 mi (2,129 km) long. It is navigable upstream to Verkhne-Kolymsk but is ice-free only from June to September. Under Joseph Stalin the goldfields of the upper Kolyma River valley held labour camps where more than one million prisoners died (1932–54).