Omolon

The Omolon () is the principal tributary of the Kolyma in northeast Siberia. The length of the river is . The area of its basin is . The Omolon freezes up in October and stays under ice until late May through early June. The lower are navigable.
It begins in the Kolyma Highlands, Magadan Oblast, less than from the Sea of Okhotsk, flows north, forms part of the border of Magdan and Chukotka, crosses Chukota, briefly enters the Sakha Republic and joins the Kolyma upstream from the Arctic. Its basin is surrounded by: (west) branches of the Kolyma, (south) Penzhina and others that flow south, (east) Anadyr and (northeast) Bolshoy Anyuy. The upper Omolon is subalpine in the highlands, the middle is boreal forest and the lower part tundra. There is a Zakaznik in Chukotka to protect the forests.
Its main tributaries are the Molongda, the west-flowing Oloy (at , the largest tributary), Oloychan, Kedon and Ango.