Adaptation to climate change in mountains is a dynamic social–ecological process, emerging from the complex interactions within and between social and ecological systems rather than solely from natural processes or human decisions. We introduce a novel analytical framework to assess these social–ecological relations in nature-based adaptation, categorizing them into social (people–people), ecological (nature–nature), and social–ecological (people–nature) interactions. By applying this framework to 25 case studies (including >10 in mountains), we examine the connections among these relations and identify distinct archetypes of social–ecological adaptation. Our findings indicate that adaptation actions incorporating stronger people–nature interactions also engage a greater number of social and ecological relations. We define four adaptation archetypes along a spectrum of people–nature interaction: (i) nature control, (ii) biodiversity-based, (iii) ecosystem services-based, and (iv) integrated approaches. This study advances the understanding of nature-based adaptation by emphasizing the need to integrate diverse social and ecological interactions, particularly in mountains. Our insights provide valuable guidance for the design and implementation of effective adaptation strategies and policies in mountains.