Arga-Yuryakh (Rassokha)

The Arga-Yuryakh (Арга-Юрях; Арҕаа Үрэх, Arğaa Ürex) is a river in Sakha Republic (Yakutia), Russia. It is a tributary of the Rassokha of the Alazeya basin. The river has a length of 312 km and a drainage basin area of 5600 km2.

The river flows north of the Arctic Circle, across desolate tundra territories of the East Siberian Lowland. Its basin falls within Srednekolymsky District. The name of the river comes from the Yakut "Arğaa-ürex" (Арҕаа-үрэх), meaning "western river".

Course
The Arga-Yuryakh has its sources at the confluence of the 21 km long Zeya and the 20 km long Taba-Bastaakh in the southern slopes of the Ulakhan-Sis. It flows roughly southwards away from the range, first following its southern flank eastwards, then bending southwards into a region of lakes of the Kolyma Lowland. The river meanders strongly, heading southeastwards across the vast lake area. Finally it meets the left bank of the northward flowing Ilin-Yuryakh. The confluence of both rivers forms the Rassokha, the largest tributary of the Alazeya.

Tributaries
The main tributaries of the Arga-Yuryakh are the 126 km long Achchygyi-Yurekh (Аччыгый-Юрэх) on the right, as well as the 62 km long Ot-Yurekh and the 50 km long Kusagan-Yurekh on the left. The river is frozen between late September or early October and late May or early June.

The Arga-Yuryakh is fed by snow, rain and ice. The river basin is marked by permafrost, swamps and lakes, the lake surface taking 15.2 % of the total basin area.