Human interactions with freshwater blue spaces promote various benefits to well-being, which can be framed by the cultural ecosystem services (CES) concept. However, small natural mountain lakes remain scarcely explored in this regard, although a comprehensive understanding of their CES is needed to promote sustainable use. To support landscape management and planning, our aims were therefore to (1) assess multiple elements of human interactions from a CES perspective (i.e., natural assets, relevant CES, benefits to subjective well-being, and pressures/threats) and (2) to evaluate the potential of integrating different socio-cultural approaches in terms of knowledge generation and applicability. By combining an online survey, social media data and participatory stakeholder workshops conducted in the context of the European Alps, we were able to capture social perceptions in quantitative, qualitative, and spatially explicit terms. Complementarity of the approaches was evident, also considering aspects of scalability, social representation, and generalisability of findings. Convergence of findings emphasised the importance of intangible benefits to well-being such as connection to nature, relaxation, and peace, but partly limited the overall information gain. Thus, the integration of socio-cultural approaches can promote more effective knowledge generation, as none of the approaches alone was sufficient to capture all the elements under consideration while yet satisfying all aspects of applicability. To further operationalise the integration of CES into planning processes, future research could aim to quantify human interactions with mountain lakes and associated well-being outcomes, and deepen the understanding of potential conflicts arising from human use of CES as revealed by this study.