Bolshaia Kuropatochia

or Sana-Iuriakh, a river in the Yakut ASSR. It is 391 km long, has a basin area of 6,240 sq km, and rises in the Kolyma Lowlands. Flowing northward along the tundra among a myriad of lakes, it enters the East Siberian Sea, forming an estuary. It is fed by snow and rain. It freezes over in winter, and huge ice layers are formed in its basin.