Glacial mountain environments are changing rapidly as a result of climate change and the expansion of nature-based recreation. Anticipatory planning to adapt to such changes is a key management challenge. The aim of this study was to explore how adaptation planning for recreation sites in these areas can be supported using participatory scenario planning (PSP). For this purpose, a study area in southeast Iceland was chosen where management is likely to be heavily impacted in the near future. PSP involves local stakeholder workshops in which participants generate maps reflecting plausible glacial land cover and land use in the near future. This process takes place in stages, including the identification of potential drivers of land-use change, development of multiple land-use scenarios, and examination of the potential consequences of these scenarios and options for adapting to them. The study demonstrates that PSP can be a valuable tool to support recreational land-use planning in glacial landscapes, and to improve anticipatory adaptation to potentially undesirable future changes. PSP also has the potential to provide salient and usable knowledge for local stakeholders, stimulate stakeholders to elaborate on long-term changes and associated uncertainties through scenario construction and visualization, provide insight into the adaptive capacity of current recreational planning systems, and reframe stakeholders' guiding assumptions to encourage a more future-oriented mentality. This approach could be valuable in other glaciated mountain areas and in recreation areas where there are multiple significant future changes in landscape attributes, processes, and uses at play simultaneously.