Leopold, Estella (1927-2024)

  • By David B. Williams
  • Posted 3/27/2010
  • HistoryLink.org Essay 9378
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Estella Leopold, daughter of famed conservationist and writer Aldo Leopold, earned her own renown through her pioneering work as a conservationist and scientist. As a conservationist, she is best known for her work obtaining protection for the stunning fossils near Florissant, Colorado, an area that became a national monument in 1969. That battle was prompted by her scientific work studying pollen, particularly on plants that lived in the Rocky Mountains around 40 to 35 million years ago. As she said at the time “How can man keep a perspective on his direction and life’s path if he loses track of the routes that life has followed before him?” (History, 21). After moving to Seattle in 1976, she continued to speak out on behalf of the environment, in both wild places and in an centers such as the University of Washington campus. She also completed important pollen studies on local sites, including landmark work that helped put together the scientific story of one of the most dangerous earthquake zones in the country. 

Youth at the Shack

Estella Bergere Leopold was the youngest of the five children born to Aldo (1887-1948) and Estella Leopold. She was the only one born in Madison, Wisconsin, where her father had moved in 1924 to work for the United States Forest Service as Assistant Director of the Forest Products Laboratory. Her brothers were A. Starker Leopold (1913-1983), Luna B. Leopold (1915-2006), and A. Carl Leopold (b. 1919-2009). Her sister was Nina Leopold-Bradley (b. 1917).  

She credited her lifelong interest in science and the outdoors to her parents. In 1935, they bought a re-built chicken coop, dubbed “The Shack,” along the Wisconsin River, near Baraboo, Wisconsin. Those 80 acres make up the property made famous by her father in his best known book, A Sand County Almanac. “On this sand farm in Wisconsin, first worn out and then abandoned by our bigger-and-better society, we try to rebuild, with shovel and axe, what we are losing elsewhere. It is here that we seek – and still find – our meat from God” (Leopold, viii). 

The family would spend weekends and summers at the property. “Dad never even encouraged us to come. He would say 'Your mother and I are going to the Shack for the weekend, anybody want to come?' Well, of course we sometimes would stay home, but most of the time we realized we were really having a better time coming to the Shack,” she said (Lemmon interview). Now owned by the Aldo Leopold Foundation, the Shack became a National Historic Landmark on January 16, 2009. 

As a child, Leopold kept some unusual pets, including a squirrel given to her by the postman. One time a spring flood prevented her from reaching the Shack with the squirrel so she ended up swimming across a marsh with the squirrel perched atop her head, which rather delighted her father. Her other pet was a crow; it, too, often led to some mischeavous moments including the time Leopold took the bird into a washroom and sat him on the hot water tap tied to a string. “All of a sudden, two women come bursting out of the washroom and came tearing across. They announced to the conductor who was standing there, “There’s a raven in there, there’s a raven in there!” We finally got on the train. The dog was checked and the crow, we wrapped in Dad’s newspaper and just held him, like so. Dad was reading the rest of the newspaper and pretending that he didn’t know me, I think” (Lemmon interview).


Leopold graduated from the University of Wisconsin in 1948 with a degree in botany. As a child she wanted to be a entomologist. “I guess when I was somewhere between 8 and 12 we were at home and I approached Dad and said that I wanted to become an entomologist, a ‘bug-ologist.’ He looked at me and lit his pipe and kind of talked about, 'Well, let’s talk about this. Why did you want to become an entomologist?' I said, 'Well, all of the other fields are taken.' Nina was a Geographer, Luna is a Hydrologist, Starker is in wildlife ecology and Carl is a Botanist. There wasn’t anything left but entomology! So Dad said, 'Well, I’ll tell you what dear, on Monday let’s go down to the book store and we’ll get a copy of Norman Fassett’s Spring Flora of Wisconsin and a vasculum,' which is what we used to collect plants in; 'and let’s see what you can do with that, okay?' And he did. I did, the very next weekend. I was right up here, over the next hill and my first plant that I identified was a big thrill. Lysimachia quadrifolia. I brought it to him with great pleasure. I was hooked. I was a botanist, and that was how it happened,” she said (Lemmon interview).  

Two years after her undergraduate program, she completed her master’s, also in botany, from the University of California at Berkeley, followed in 1955 by a Ph.D. in botany, from Yale University. It was at Yale that she began to focus on pollen. “I got into pollen strictly by accident. I was going to go to UCLA for plant physiology but a friend said it was a horrible place for a woman to work on her Ph.D.; it could take 10 years. When I asked how did he know, he said, ‘my wife.’ So when my brother said, come to Yale, I did,” she said (Williams interview). 

Leopold still planned on a Ph.D. in plant physiology but her advisor asked her whether she had considered pollen. She knew a bit about pollen and that there were problems one could solve by studying it, but working with pollen was particularly tough. When her advisor asked if she was afraid of the challenge, it piqued Leopold, who quickly fell in love with pollen. 

The study of pollen, part of the discipline of palynology (the study of spores and pollen), focuses on the microscopic mass of grains containing the male gametes of seed-producing plants (for example, conifers and angiosperms). Each plant produces a specific type of grain, which can be identified using a microscope by its characteristic shape. Because plants produce thousands to millions of grains of pollen, which can get blown or washed into lakes, it is well-represented in the fossil record.   

Denver Years 1955-1976 

The Paleontology and Stratigraphy Branch of the United States Geological Survey (USGS), based in Denver, hired Leopold out of her Ph.D. program. One of her earliest projects was to study pollen taken from deep cores in several atolls in the south Pacific Ocean. The work took place on Eniwetok and Bikini atolls, coral lagoon islands used by the United States during the 1940s and 1950s to test nuclear weapons.  Her initial research, described in a 1958 paper (where curiously, despite her Ph.D., she was called Miss Estella Leopold), used pollen collected from cores drilled from 800 to more than 2,000 feet below the surface. Leopold showed that during the Miocene Epoch (between 23 and 5 million years ago) a dense tropical forest had covered the coral islands. Over time that forest had been buried as the volcano, or seamount, that the coral and plants had colonized slowly subsided. In 1963 and 1969, Leopold published more substantial and formal analyses of the pollen from Eniwetok Atoll. 

The idea that coral atolls formed atop subsiding volcanoes was first proposed by Charles Darwin, in Chapter 20 of his Voyage of the Beagle (1839):

“I venture, therefore, to affirm, that on the theory of the upward growth of the corals during the sinking of the land, all the leading features in these wonderful structures, the lagoon-islands or atolls, which have so long excited the attention of the voyagers, as well as in the no less wonderful barrier-reefs, whether encircling small islands or stretching for hundreds of miles along the shores of a continent are simply explained.”

Leopold’s research was an essential first step in proving that Darwin was correct.

During her time at the USGS in Denver, she also focused intently upon the Tertiary (66 million years ago [mya] to 2 mya) Period plants of the Rocky Mountains, in Colorado, Wyoming, and Idaho. Her work has helped reconstruct the paleoenvironments of that era and showed how the plants responded to mountain building and volcanism. By studying pollen from cores and surface sites, she offered some of the earliest, best documented, and most thorough evidence for how plants respond to climate change.  

The Florissant Fossil Beds

Her work with the Tertiary flora of Colorado led Leopold to a spectacular fossil deposit, 35 miles west of Colorado Springs near the town of Florissant. Known for its petrified forest since the late 1800s, the beds formed from mudflows, streams, and lakes that existed around 34 million years ago. A mixture of fine-grained mud and ash from nearby volcanoes helped preserve a myriad of insects, spiders, mammals, fish, and plants in exquisite detail. Paleonotologists have found more than 1,700 species from more than 50,000 specimens. 

The fossil beds, which cover of an area of more than 6,000 acres, were privately owned when Leopold first began to study the paleobotany. In 1962, a formal proposal was made to the National Park Service to protect the land as the Florissant Fossil Beds National Monument. Despite public support, the bill languished in Congress and in the late 1960s, Leopold teamed with Beatrice Willard and Vim Crane (Vim Crane Wright) to form the Defenders of Florissant. On July 9, 1969, they brought suit in Federal Court to block planned construction by a real estate company (History, 21). Judge Hatfield Chilson denied the motion but an appeal placed by attorneys Victor Yannacone and Richard Lamm (governor of Colorado 1975-1987) was granted and construction ended. The stay would, however, run out in August so the Defenders announced that if bulldozers returned they would block them. Crane (Vim Wright) said at the time. "I went right out and had my hair fixed, put on my pearls and high heels ... . I thought no self-respecting bulldozer driver would run over a woman in pearls and high heels" (History, 22). 

The work of the Leopold and the Defenders group drew enough publicity to the fossils that Congress finally acted. On August 20, 1969, President Nixon signed the bill creating the 6,000 acres of the Florissant Fossil Beds National Monument. "We thought and still think the values in this property were extremely varied and wonderful," Leopold says. "They were spiritual, paleontological, biological, recreational and aesthetic values, all at this one fossil site" (The Gazette). For this work, she was a co-recipient of the 1969 Conservationist-of-the-Year-Award from the Colorado Wildlife Federation.

Working Quietly for Conservation

It was neither the first nor last time that Leopold fought to protect the environment, though some of her early conservation work was less public, because of her employment with the USGS. In 1960s and 1970s, Leopold helped stop proposed oil shale development in western Colorado. She led field trips for the National Audubon Society and served on the Colorado state Oil Shale Committee on Environmental Protection. She also anonymously wrote white papers, providing important background research on the ecologic and economic problems with oil shale development.  

She also worked to stop dams in the Grand Canyon. As part of the Central Arizona Project to bring water to Tucson and Phoenix, Arizona’s congressional representatives proposed building two hydroelectric dams, at Bridge Canyon and Marble Canyon, which would flood parts of the Grand Canyon. During the late 1950s and 1960s, Leopold again anonymously wrote many background papers essential for dam opponents such as David Brower and the Sierra Club. Although Brower and others blocked the Grand Canyon dams, their victory occurred in part because they capitulated and allowed dams, primarily the Glen Canyon Dam, to be built elsewhere. “Because of that I never joined the Sierra Club,” Leopold said (Williams interview).  

She was on the national boards of The Nature Conservancy, National Audubon, and the Environmental Defense Fund, as well as local boards of Colorado Open Space Council (co-founder), Denver Audubon Society, and the Rocky Mountain Center on the Environment. For her many efforts over many years, Leopold won the Keep Colorado Beautiful annual award in 1976.

Throughout all of her efforts to protect the environment, Leopold continued to do important pollen research in the Rockies and Alaska. Her insightful and groundbreaking work led, in 1974, to her election to the prestigious National Academy of Sciences, where she joined her brothers Luna and Starker. She was of the few woman elected to the Academy at the time, plus no other family has had as many siblings in the Academy.

Life and Work in the Pacific Northwest

During Leopold’s last nine years at the USGS, she also taught in the Department of Biology at the University of Colorado. “I got the bug and discovered I liked to teach,” she says (Williams interview). The University of Wisconsin, where she taught for the 1971-1972 school year, offered her a job but she couldn’t leave the USGS in time. By 1976, she was able to leave and accepted an offer to become director of the Quaternary Research Center (QRC) and professor of botany and forest sciences at the University of Washington. At QRC, she headed a multidisclipinary team of anthropologists, botanists, glaciologists, oceanographers, forest ecologists, and civil engineers, which  focused on the last 1.8 million years of Earth history, the time period designated as the Quaternary.

After moving to Seattle, Leopold added to her past research by including two areas: the I-5 corridor (Puget lowlands south to Vancouver) and China. Leopold’s research and that of her students helped reveal how ecosystems responded during the past 20,000 to 25,000 years. For example, south of the southern most extent of the Puget lobe – the massive glacier that covered the area – trees now associated with high-elevation areas of Eastern Washington, such as Engelmann and Sitka spruce and Pacific silver and grand fir, cloaked Western Washington. When the ice melted, more luxuriant vegetation quickly invaded, and within 1,000 years (by 11,000 years before present (B.P.) Douglas fir had spread north from south of the Columbia River to the Canadian border. Some areas, particularly in the south around Vancouver, remained more open and savanna-like. Garry oak, camas lily, bracken, and chinkapin (a tree now rare in the state) covered these prairies for several thousand years but by around 4,500 years B.P. the climate had begun to switch and conifers began to replace the grasslands.

Like her father, Estella was in essence a story teller but for her the action and drama came from the pollen and how plants respond to climate change. In a 1999 paper, she wrote “The romance of a lost biome dominated by ice-age mastodons, and a warmer time when prairie Indian cultures were in their heydey, can be inferred from fossil evidence, and can be read between the lines of the pollen story” (Boyd, 139).  

For Seattle residents, Leopold’s work at a Restoration Point on Bainbridge Island may be the most earth shattering. In a study released in Science on December 4, 1992, she and colleagues from the USGS reported on a fault system that cut across Seattle. Peat deposits, beach gravel, and humus indicated that sometime between 500 and 1,700 years ago an earthquake generated as much as seven meters (23 feet) of uplift. The study was part of five reports in Science that described what is now known as the Seattle Fault Zone, a previously undescribed, several-mile-wide area of crustal weakness running from about Issaquah, under Qwest Field and T-Mobile Park, through Alki Point and Restoration Point to Hood Canal. It is potentially the most devastating earthquake zone in the region.   

Leopold in China

Leopold’s long-term interest in China and its paleobotany began in 1975, when she was deputy chairman of a National Academy of Sciences interdisciplinary trip to China. Known as the Paleoanthropology Delegation, it was run under the auspices of the Committee on Scholarly Communication with the People’s Republic of China. The delegation hoped to share scientific information, learn about the state of science in China, and examine early man, primarily the collections associated with “Peking Man,” which were found between 1929 and 1937 and then lost during World War II.  

Two years after the return of the delegation, the National Academy of Sciences published a trip report, totaling nearly 200 pages. Leopold’s section focused on her interaction with fellow Chinese palynologists. She concluded that Chinese palynologists had done much work but that a lack of ideas and stimulus were the greatest barrier and that the state of science was decades behind what was happening in the West.  

Her time in China led her to a multi-decade long collaboration with Chinese paleobotanist Gengwu Liu, who had heard one of her talks in China and later arranged for a fellowship to come work in Leopold’s lab. Over many years, she, Liu, and others helped raise the standards of paleobotanical research in China and helped show affinities between the flora of China and western North America.

For the Environment

Thoughout her more than three decades in Seattle, Leopold remained steadfast in her activism and community involvement. As a member of the Governor's Advisory Council for High-Level Nuclear Waste Management from 1982 to 1987, she was part of the 6-5 majority supporting a moratorium against shipments of high-level nuclear materials through the Strait of Juan de Fuca and Puget Sound. In addition, she worked with other scientists to show how unsafe nuclear waste would be in the subsurface basalt below the Hanford Reservation in Eastern Washington. “When we pulled up cores, the basalt was like Pringle’s potato chips. It was clear that the rock was very pervious and would not store any leaked waste,” she said (Williams interview). 

Around Seattle, she was active in working with people such as Tony Angell (b. 1940) to get the green spaces around Union Bay designated into a nature park; co-founded a group to protect Ravenna Park, and co-founded the anti-UW Law School group (formed to oppose the new law school building), Friends of UW Environment (“Pronounced Phooey,” she says), to protect campus trees and address issues of traffic and parking. 

Activities and Legacies

In order to return to teaching, Leopold resigned as director of QRC and kept her position as professor in the Department of Botany and College of Forest Resources. Seven years later she became professor of botany and environment studies, and was part of the UW’s Institute for Environmental Studies, an interdisciplinary program. She ended up resigning from the institute over conflicts with a new director.

In 1992, Leopold was elected to the American Academy of Arts and Sciences, followed in 2000 by her election to the American Philosophical Society. This was also the year she became a professor emeritus at the University. 

In 2005, she made another significant contribution to the UW when she and her brother Luna donated $1 million to the Burke Museum of Natural History and Culture to establish an endowed curator position in paleobotany. The gift was matched by a $500,000 grant by Campaign UW. In 2006, Caroline A. E. Stromberg became the Estella B. Leopold Assistant Professor in Biology and Curator of Paleobotany at the Burke Museum. The new position was a fitting legacy for someone who devoted more than six decades to not only understanding the world better but also to ensuring that it is protected for future generations to study and enjoy.

Estella Leopold died on February 25, 2024, at age 97. 


Jim McChristal, A History of Florissant Fossil Beds National Monument: In Celebration of Preservation (National Park Service, 1994); Aldo Leopold, A Sand County Almanac and Sketches Here and There (New York: Oxford University Press, 1949), viii; Rick Lemmon interview with Nina Leopold-Bradley and Estella Leopold, Daughters of Aldo Leopold, The Shack, Baraboo, Wisconsin, September 11, 2003; David B. Williams interviews with Estella Leopold, Seattle, March 9 and 25, 2010; Indians, Fire, and the Land in the Pacific Northwest ed. by Robert Boyd, (Corvallis, Oregon: Oregon State University Press, 1999); Harry S. Ladd, Fossil Land Shells from Western Pacific Atolls, Journal of Paleontology, Vol. 32, No. 1, January 1958, p. 183-198; Deb Acord, “Protecting Florissant Fossil Beds still a cause worth celebrating,” The Gazette (Colorado Springs, CO), August 27, 2004, Out There p. 1; Paleonthrolopology in the People’s Republic of China: A Trip Report of the American Paleoanthropology Delegation ed. by W.W.Howells and Patricia Jones Tsuchitani (Washington, D.C.: National Academy of Sciences, 1977); Robert Bucknam, Eileen Hemphill-Haley, and Estella B. Leopold, Abrupt Uplift Within the Past 1700 years at Southern Puget Sound, Science 258, December 4, 1992, No 5088, p. 1611-1614. Note: This entry was updated on February 27, 2024.

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