The river Gaula runs through the 145-kilometre (90 mi) long valley from the mountains in Røros Municipality near the lake Aursunden to the Trondheimsfjorden.

The narrow valley runs northwards from Røros to the Haltdalen area, where it widens some, turns and heads generally to the west to the village of Støren.

At Støren it turns again and heads north through what is now a wide, agricultural valley until it reaches the sea just south of the city of Trondheim.

Røros Municipality is often (traditionally) counted as a part of the district, even though it lies outside the actual Gaula river valley.

This tremendous landslide then created a quickly rising lake that began to flood the valley up to 15 kilometres (9.3 mi) upstream from the dam.