The Sundrun is a river in the Sakha Republic (Yakutia) of the Russian Federation. It is 314 km long, and has a drainage basin of 4170 km2.

Course

It has its sources in the Ulakhan-Sis Range and flows roughly northeastwards across the Kondakov Plateau. 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. The Sundrun River freezes up in early October and remains icebound until June.

Tributaries

The main tributary of the Sundrun is the 235 km long Maly Khomus-Yuryakh (Малый Хомус-Юрях) from the right.

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. The lesser white-fronted goose, Brent goose, Bewick's swan and the spectacled eider are also found in the Khroma-Sundrun Interfluvial Area. There is also a wild reindeer population in the Sundrun basin.

Sundrun Kekurs

The "Sundrun Kekurs" (Сундрунские кекуры) are the natural kigilyakh-type rock formations of the Ulakhan-Sis Range and Suor Uyata, located in the upper course of the river.