The environmental management of rivers faces a substantial geographical problem: due to their elongate shape and their position at the valley bottom, the area that they cover is fragmented by territorial borders. Therefore, only very few river basins or substantial parts of them have yet been assigned as dedicated sites (nature reserves, parks, etc.). Commonly, these sites occur in a scattered pattern within the riverscape and belong to different administrative units, which makes coordinated conservation and management difficult. Moreover, access to documented results is limited, and the practical experience of site managers remains an unexploited source of knowledge. Here, we compare two sites, the Loire valley (with a large zone protected by a UNESCO World Heritage Site, Natura 2000 sites network, and a French Regional Natural Park, which are partially overlapping) and the Dordogne watershed (entirely belonging to the first UNESCO Biosphere Reserve of this kind and a French Public Basin Establishment). The targets concerning conservation and sustainable management of these sites differ, however, they all focus on cultural and ecological sustainability. Combining reports and interviews with the respective site managers with literature back searches, and analyzing these data with case study and content analysis methods, we addressed the following questions: (1) What are the priority management issues, including threats that impact the site from outside, and how are they tackled? (2) Who are the stakeholders and what are their interrelationships? (3) What are the dynamics of socio-ecological systems related to riverscapes? (4) How to conserve and manage riverscapes with socio-ecological approaches? and (5) What are the best management practices from the Loire River Valley and Dordogne basin cases that can be harnessed in other riverscapes? We show that the Loire River Valley and Dordogne River basin present positive examples for a transdisciplinary socio-ecological approach to conserving and managing riverscapes, integrating diverse stakeholder knowledge in participatory decision-making, recognizing the natural character of the river, and coupling social and hydrological systems. The greatest achievement of the site managers is that they have built up trust and found feasible solutions for satisfying the different interests of diverse stakeholders. Ingenuity and perseverance, combined with excellent moderation skills, were the most important characteristics leading to success. The overall target of this paper is to evidence problems and their solutions concerning the management of dedicated sites that are connected to rivers, to encourage the creation of further sites of this type, and to facilitate cooperation between different types of dedicated sites.