This river is very popular among the natives and is one of the many tributaries of the glacial river Lagarfljot. It is only about 15 minutes driving distance from the town Egilsstadir. There are many good fishing spots and the surroundings are very attractive.

The catch consists mainly of brown trout and char. The river is named after the mountain Thingmuli, where one of the ancient district parliaments were held in the past. It runs through the valley Skriddalur, The Landslide Valley, and one of the many landslides closed the valley in the past and created the lake Skriduvatn, the origin of the river. The distance from the capital is about 710 km.