The Klyazma, a river in the Moscow, Nizhny Novgorod, Ivanovo and Vladimir Oblasts in Russia, forms a left tributary of the Oka.The river has a length of 686 kilometres. The area of its drainage basin is 42,500 square kilometres. The Klyazma usually freezes up in November and stays under the ice until mid-April, although in faster-moving stretches ice-free water occurs until the air temperature drops below −10 °C.
The largest tributaries of the Klyazma include:
Wikipedia https://en.wikipedia.org/wiki/Klyazma
Coordinates 55°57'10.651" N 37°24'46.684" E