The Nerl (Russian: Нерль) is a river in the Yaroslavl, Ivanovo, and Vladimir Oblasts in Russia, a left tributary of the Klyazma (Volga's basin). The river is 284 kilometres (176 mi) long, and its drainage basin covers 6,780 square kilometres (2,620 sq mi).^[1] The Nerl River freezes up in November or December and stays under the ice until April. Its main tributary is the Ukhtoma.