Eurasian beaver, Castor fiber has been restored to England's natural fauna following a trial reintroduction located in the country's southwestern region. Beavers characteristically generate profound and frequently beneficial shifts to river dynamics, nutrient cycling, biodiversity, and human cultural experience, but can also be associated with unwanted human interactions, impacts and costs. Consequently, an important objective of the trial design was to ensure conservation leadership, monitoring and mitigation for problems such as burrowing, damming and flooding, and damage to valued trees. To understand how these developments are perceived and accepted, implicated key stakeholder mental models were elicited and explored, using fuzzy cognitive map techniques. Analysis showed broad alignment of ecological understanding between stakeholders. Social perspectives showed marked divergence, a focus of concern as social conflict can undermine otherwise ecologically viable conservation benefits. To investigate perceived effectiveness of trial conservation measures, stakeholder models with and without conservation actions were experimentally compared under dynamic analysis. Overall, the findings indicate that actions taken are sustaining beaver acceptance and limiting persecution. Of stakeholder groups examined, farming appeared most susceptible to model divergence, but also strongly protected by mitigation. This is important as reconciling mental model differences is considered a necessary element in building socio-ecological system resilience. These findings highlight mental model analysis as a valuable aid to assessment of social dimensions of conservation policies. Further, mental modelling could help to focus how farm payment reform in the U.K. and similar economies might be used to support leadership and mitigation designed to improve human-beaver ecosystem resilience.