The Cévennes National Park is a regulated and inhabited area that attempts to reconcile environmental and socio-economic issues. It must compromise with all the actors in the area who hold traditional, technical, and scientific knowledge. This learning process in co-management is an invitation to dialogue, negotiation, and even the comparison of local practices. Since the creation of the Park in 1970, a scientific approach to local ecological knowledge has accompanied the evolution of social and ecological issues. The research or conservation programmes provide a valuable perspective on the position of local actors within the framework of environmental policies. Are traditional knowledge and know-how relevant from the point of view of the preservation of biodiversity?