The celebrated 1972 Stockholm environmental conference focused attention on the condition of the world's environment. A twenty year retrospective summary is provided by the introduction and specialty papers on all facets of mountain society and habitat relationships. Theories, models and paradigms that guided mountain research are critically examined. Specific attention is given to the application of the ecology paradigm. Contemporary discoveries and developments about resource management in mountains are elucidated. Assessments of the mountain environment, including wildlife habitat, tourism and recreation, forests, hazards, deforestation, food plant biodiversity, risk and hazard, are provided by the specialty articles. These papers were prepared for the 1992 Earth Summit in Rio de Janeiro.