The Swedish conservation work with the endangered thick shelled river mussel (Unio crassus) has so far included inventory work, status descriptions and establishment of action plans by the Swedish Environmental Protection Agency, EPA (2006). Within this project, UC4LIFE, however, we will implement actions beneficial for Unio crassus at 12 project sites, strategically distributed within its distribution range in Sweden. The project sites are located in eleven river systems, their catchment areas covering >30% of its historical distribution area. The project sites have all been specifically identified and regarded as suitable for the actions proposed. The main criteria for those sites being chosen are: 1) Poor conservation status, alternatively extinct populations of Unio crassus at the sites. 2) The disturbances for Unio crassus population decline identified at the sites. 3) The proposed actions should result in significant and positive responses on the Unio crassus populations and its habitats, even outside the project sites (ie downstream and/or upstream the project site). 4) Robust landowner relationships at the sites.