The Oulu River was rich in salmon until the beginning of the 1940s, prior to its harnessing for water power production, which stopped the salmon from migrating in the river. After the completion of the Merikoski fishway in 2003, migrating fi sh have again had access to parts of the river, and the idea of bringing them back to the upper part of the Oulu River has emerged. The conditions for salmon migration and spawning in this river formerly rich in salmon were the target of this project. In addition to the Oulu River, the scope of the project also included the River Lososinka, which flows through the town of Petrozavodsk and where salmon migration upstream has also been prevented for 300 years. Salmon spawning has only been possible within a stretch of a few hundred meters in the river delta. The power plants are no longer operational, but there are three dams left in the river. The upper part of the river is in a natural state and quite suitable for salmon spawning. The River Lososinka could potentially be a highly yielding river for salmon, if the necessary fish ways could be built. The main purpose of the project was to determine the conditions for bringing back fish of value in constructed water systems as well as find technical solutions to remove the obstacles to migration. The purpose was also to develop a cooperation network of specialists, research facilities and authorities for future projects.