‘By the early 1920s, Leopold had concluded that a particular kind of preservation should be embraced in the national forests of the American West. He was prompted to this by the rampant building of roads to accommodate the “proliferation of the automobile” and the related increasingly heavy recreational demands placed on public lands. He was the first to employ the term “wilderness” to describe such preservation. Over the next two decades he added ethical and scientific rationales to his defense of the wilderness concept. In one essay, he rhetorically asked “Of what avail are forty freedoms without a blank spot on the map?” Leopold saw a progress of ethical sensitivity from interpersonal relationships to relationships to society as a whole to relationships with the land, leading to a steady diminution of actions based on expediency, conquest, and self-interest. Leopold thus rejected the utilitarianism of conservationists like Gifford Pinchot and Theodore Roosevelt.
By the 1930s, Leopold was the nation’s foremost expert on wildlife management. He advocated the scientific management of wildlife habitats by both public and private landholders rather than a reliance on game refuges, hunting laws, and other methods intended to protect specific species of desired game. Leopold viewed wildlife management as a technique for restoring and maintaining diversity in the environment rather than primarily as a means of producing a shootable surplus.
The concept of “wilderness” also took on a new meaning; he no longer saw it as a hunting or recreational ground, but as an arena for a healthy biotic community, including wolves and mountain lions. In 1935, he helped found the Wilderness Society, dedicated to expanding and protecting the nation’s wilderness areas. He regarded the society as “one of the focal points of a new attitude—an intelligent humility toward man’s place in nature.” ‘–wikipedia, 2012-06-28