It originates in Rautasjaure (Lake Rautas) in the mountains of northwestern Lapland, at an elevation of 560 m above mean sea level.

After 6-10 km, the branches meet again and the river continues in a southeasterly direction.

It passes by the village of Käyrävuopio shortly before the stream Tiansbäken (Vuonajohka) flows into the river from the right/south.

Then it continuous through uninhabited land, with Pahtajoki flowing into it on the right, before passing by a place where a footpath leads toward the river from the south (see photo).

Finally, it flows into Vahkujávri, which is part of the Torne River, at an elevation of 327 m, after nearly 135 km.