This study in visual communication is an examination of how visual images used in persuasive environmental media campaigns reflect the 'social construction of nature.' It focuses on films and videos related to the issue of wilderness preservation in America; it addresses the ways in which these portray wilderness as a visual entity, and points to implications for influencing attitudes, behavior, and policy. The study includes analyses of forty films which are categorized institutionally, according to the type of organization which produced them: (1) environmental advocacy groups, such as the Sierra Club and the Wilderness Society, (2) government agencies, such as the National Park Service, and (3) private, run-for-profit corporations. The American landscape art tradition provides the aesthetic and historical context for the analysis of wilderness images in these films. The 'ways of seeing' constructed by nineteenth-century landscape paintings and photographs are reflected in the films' depictions of national parks, unprotected old-growth forests, and other wilderness environments. Studies in landscape art, as well as empirical research and landscape assessment theories, suggest several analytic categories applicable to these films, including various compositional devices ('Claudian' frames, recessive planes, 'prospect' and 'refuge' symbolism, etc), and compositional elements (snow-covered mountains, reflecting pools of water, carefully placed human figures, etc). These produce 'positive' landscape images, and encourage viewers' imaginative entry into them. The films rely heavily on visual contrasts between these 'positive' images and 'negative' images depicting technological incursion into wilderness (by modern day 'machines in the garden'--chainsaws, bulldozers, automobiles, motorhomes, etc), and other forms of human manipulation (stumps, clear-cuts, 'built' elements, pollution, etc). These contrasts are consistent with the ideological antinomies of American Western films (wilderness vs. civilization, nature vs. technology, etc), but are expressed in ways unique to these documentaries, using devices such as the 'paradise lost structure,' the 'montage of destruction,' etc. The films also exhibit ideological similarities and differences among their respective producing organizations. The U.S. Forest Service's films reveal affinities with those by private corporations, while the National Park Service's express concern with ecosystem preservation that is close in spirit to the concerns of environmental advocacy groups.