It has its sources in the Ulakhan-Sis Range and flows roughly northeastwards across the Kondakov Plateau.[2] Leaving the uplands, it crosses the Yana-Indigirka Lowland tundra, part of the greater East Siberian Lowland. It flows first in a roughly eastern and then, more than halfway through its course, in a northern direction. Its mouth is in the East Siberian Sea at the western end of the Kolyma Bay.[3] The Sundrun River freezes up in early October and remains icebound until June.
Tributaries
The main tributary of the Sundrun is the 235 km (146 mi) long Maly Khomus-Yuryakh (Малый Хомус-Юрях) from the right.[1]
Khroma-Sundrun Interfluvial Area
The Kytalyk Wetlands, located between the Sundrun and the Khroma, are an ecologically important area, providing a favorable habitat for many rare animals. It is practically uninhabited and full of lakes and marshes. Siberian cranes are abundant in the Sundrun River wetlands.[4]