On the short list of great environmental thinkers, Aldo Leopold is near the top, next to John Muir and Henry David Thoreau. Leopold’s famous collection of essays, A Sand County Almanac, is heralded today as one of the seminal texts of twentieth century conservation. Less well known is that Leopold formed personal and professional relationships with Cook County forest preserve staff during the last decade of his life and had a direct influence on the structure and philosophy of the Forest Preserve District. Leopold passed away in 1948 and A Sand County Almanac was published posthumously in 1949.

Leopold and the Department of Conservation

Leopold’s teaching and research prompted Forest Preserve District administrators to attempt to reform the public’s use of the forest preserves by educating them about the value of the flora and fauna protected there. During the late 1930s, administrators wanted to stymie what they viewed as the public’s “unintelligent use and abuse”^[i] of the forest preserves, which included littering, driving off-road and even cutting down trees. At the urging of General Superintendent Cap Sauers, Roberts Mann (then superintendent of maintenance) asked for Leopold’s advice on how to change the public’s behavior.

Sauers had just read Leopold’s 1938 essay “Conservation Esthetic” in Bird Lore (today Audubon Magazine).^[ii] Shortly thereafter, Mann recalled visiting Leopold in Madison, Wisconsin, where Leopold was Professor of Game Management. Mann wrote, “That was the first of many pilgrimages to get our thinking straightened out. We made Professor Leopold very happy. Somebody, at last, was listening.”^[iii]

As early as 1939, Mann began citing Leopold’s insight that park administrators could only augment public use by changing public perception of protected lands: “Prof. Aldo Leopold, of the University of Wisconsin, phrases it best: ‘To promote’ perception is the only truly creative part of recreational engineering… Recreational development is a job not of building roads into lovely country, but of building receptivity into the still unlovely human mind.’”^[iv] In a 1948 presentation, Mann read that same Leopold quote and then paraphrased it: “In other words: we must entice people to use their own property and use it wisely; we must entice them to look at nature and appreciate nature; we must teach them perception.”^[v] To teach that “perception,” District staff members had begun publishing nature bulletins in 1944 and circulating them to schools all over Cook County.

In 1945, the District created the Department of Conservation, which produced the bulletins and eventually became responsible for nature center exhibitions, field training for teachers and in-school visits by forest preserve naturalists. Roberts Mann served as the Forest Preserve District’s first superintendent of conservation.

Leopold and Wildlife Management

Leopold also shared his expertise with Forest Preserve District staff by advising them about wildlife management. For instance in 1938, Mann consulted Leopold about his plans to introduce prairie chickens to the forest preserves. Leopold told him, “I do not know the Palos Hills but I think I have seen similar terrain and my guess would be that the chance for chickens is good.” He referred Mann to two wildlife biologists at the Illinois Natural History Survey (INHS) to develop a plan for stocking.^[vi]

In the 1940s, Senior Naturalist David “Doc” Thompson talked with Leopold about his methods for estimating wildlife populations. At the time, Thompson was approximating waterfowl populations using data he collected by trapping and banding migrating ducks at McGinnis Slough. In a 1945 letter to an INHS biologist, Mann wrote, “Dave and I have spent all day Saturday with Prof. Leopold. He was intensely interested in what Dave has done with our duck data and some of the trends uncovered.”^[vii]

While Mann and Thompson were seeking Leopold’s advice, they grew close to him. One of Thompson’s notes to Leopold suggests the friendship he shared with his family: “Thank Mrs. Leopold for a pleasant meal and tell her that the water color in her dining room is really fine.”^[viii] In 1953, Mann described Leopold as “my friend and mentor.”^[ix] The following year, Mann wrote in a magazine tribute to Leopold: “Six years have not dimmed the feeling of personal loss which was suffered by everyone who knew Aldo Leopold when we learned of his untimely death.”^[x]

Aldo Leopold’s writings continue to inspire environmentalists around the world. His legacy,, first conveyed through Mann and Thompson, and then passed down through the decades, remains evident in the Cook County forest preserves today.

The Centennial History Series takes an in-depth look at various chapters throughout the Forest Preserves’ 100 years. Natalie Bump Vena is a JD/PhD candidate in Northwestern University’s School of Law and Department of Anthropology. She is also the Gaius Charles Bolin Fellow in Anthropology and Environmental Studies at Williams College in Williamstown, MA. Natalie is writing her dissertation about the history of natural resources policy in the Forest Preserve District of Cook County. She grew up on Chicago’s South Side and visited the Palos forest preserves most weekends with her family.

Photo: “Aldo Leopold (1940).” Series 3/1, Box 84, Folder 5. The Aldo Leopold Archives. Aldo Leopold Foundation and UW Archives.

• [i] Roberts Mann, “Picnic Grounds in a Metropolitan Reservation.” Reprinted from Parks and Recreation. 1953. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 2, Folder 24.
• [ii] Roberts Mann, “Aldo Leopold, Priest and Prophet.”  American Forests. 1954. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 22, Folder 300.
• [iii] Roberts Mann, “Aldo Leopold, Priest and Prophet.”  American Forests. 1954. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 22, Folder 300.
• [iv] Roberts Mann, “State Park Maintenance.” A Paper Given At the First Institute in Landscape Management, New York State College of Forestry. 1939. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 21, Folder 285.
• [v] Roberts Mann, “Improve the Quality of Public Use, An extemporaneous talk made before the American Institute of Park Executives.” 1948. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 9, Folder 125.
• [vi] Letter from Aldo Leopold to Roberts Mann. March 23, 1938. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 33, Folder 501.
• [vii] Letter from Roberts Mann to Arthur Hawkins. March 3, 1945. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 4, Series 90.
• [viii] Letter from David Thompson To Aldo Leopold. June 15, 1944. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 4, Folder 88.
• [ix] Roberts Mann, “How the Park Man Should Be Prepared to Meet the Public.” 1953. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 4, Folder 82.
• [x] Roberts Mann, “Aldo Leopold, Priest and Prophet.”  American Forests. 1954. Forest Preserve District of Cook County Collection, Special Collections, University of Illinois at Chicago. Series III, Box 22, Folder 300.