I can remember Dr. A. Starker Leopold, on a zoology class field trip in Lake County, California, in 1951, telling some of his students that before long fire would be restored to national parks. It seemed a startling and revolutionary idea at the time.

Bruce M. Kilgore, 1974

More visitation, better roads, and improved accommodations—the traditional concerns of national park management—were gradually challenged during the 1960s and early 1970s by the need to address the ecological issues summarized at the Second World Conference on National Parks in 1972. Meanwhile, America's historical preoccupation with monumentalism masked the nation's failure to establish national parks of unquestionable ecological integrity. The result was renewed interest in the biological significance of the larger national parks and monuments already in existence. Again precedent could not be ignored. Granted, the old-line parks and monuments had been established with cultural rather than ecological ends in mind. Only the larger reserves, however, regardless of their imperfections, possessed the diversity of natural features necessary to begin widespread experimentation with the principles of biological management.

Among the Park Service's existing management policies, none seemed more inconsistent with the needs of plants and animals than providing opportunities for mass recreation. As overcrowding worsened, however, a few scientists occasionally spoke out against accommodating people in the parks at the expense of the natural scene. Finally, these random notes of criticism achieved special credibility in 1963, when the distinguished Leopold Committee, chaired by A. Starker Leopold of the University of California at Berkeley, released its sweeping report, Wildlife Management in the National Parks. If the document had appeared but a few years earlier, undoubtedly it would have been largely ignored. A new generation of conservation leaders, however, influenced by Rachel Carson's Silent Spring and caught up in the emotion of the environmental movement, instead found the Leopold Committee's conclusions too provocative to dismiss. [1]

Central to the committee's report was its recommendation that protection, defined as the strict maintenance of park features, must give way to greater respect for the importance of the natural forces that had brought about those features in the first place. For example, the scientists reported, "It is now an accepted truism that maintenance of suitable habitat is the key to sustaining animal populations, and that protection, though it is important, is not of itself a substitute for habitat." Habitat had less to do with artifacts or physical wonders and more to do with natural processes, such as wind, rain, and fire. It followed that habitat could not be regarded as "a fixed or stable entity that can be set aside and preserved behind a fence, like a cliff dwelling or a petrified tree." Biotic communities evolved by "change through natural stages of succession." Managers who chose to alter the parks biologically must therefore resort to the direct "manipulation of plant and animal populations." [2]

How that manipulation might be directed, and toward what ends, comprised the most significant portion of the Leopold report. "As a primary goal," the committee suggested, "we would recommend that the biotic associations within each park be maintained, or where necessary recreated, as nearly as possible in the condition that prevailed when the area was first visited by the white man." In short, the scientists concluded, "A national park should represent a vignette of primitive America." [3]

The obstacles to achieving "this seemingly simple aspiration are stupendous," the committee wrote, admitting the obvious: "Many of our national parks—in fact most of them—went through periods of indiscriminate logging, burning, livestock grazing, hunting, and predator control." Once those areas became national parks they again "shifted abruptly to a regime of equally unnatural protection from lightning fires, from insect outbreaks, absence of natural controls of ungulates, and in some areas elimination of normal fluctuations in water levels." Meanwhile, exotic species of plants and animals had "inadvertently been introduced." Finally, factors of human visitation, including "roads and trampling and camp grounds and pack stock," had taken their toll of park environments. It was small wonder that restoring "the primitive scene" would not be "done easily nor can it be done completely," the committee concluded. The point was that the National Park Service needed a new perspective from which to begin a more sensitive management program. [4]

At least among scientists familiar with the national parks, the suggestion that they be restored to their appearance at the time of European contact with North America had been discussed as early as the 1910s. [5] With the growing popularity of the environmental movement during the 1960s, more Americans, including eminent scientists such as those of the Leopold Committee, found the ideal of pristine wilderness a comforting vision in a rapidly changing world. Few at the time noted the apparent contradiction in the committee's own conclusions. Having argued that natural forces were dynamic, the committee nonetheless recommended that national park environments be restored to an approximation of their original state four hundred years earlier. Obviously the committee, much like preservationists in general throughout the 1960s, had been influenced by the opinion that human beings were disruptive and therefore were "unnatural" presence in wilderness areas. Yet another contradiction was the committee's reluctance to extend this bias to Native Americans as well as to their European conquerors. Instead, the committee endorsed manipulation of the environment by the Indians, particularly their use of fire, as a practice in keeping with the need to restore periodic burning to many park landscapes. [6]

By "natural," in other words, the committee meant "original," or at the time of European contact. Put another way, Native Americans were "original" and therefore a "natural" presence in North America. Europeans rather than Indians had been responsible for changing the continent ruthlessly and unsystematically. "The goal of managing the national parks and monuments," the committee restated, "should be to preserve, or where necessary recreate, the ecologic scene as viewed by the first European visitors." [7]

The use of the term "visitors" to describe European pioneers again strongly implied that they and their descendents, not Native Americans, were the unnatural element in the New World. As white Americans moved westward, wildlife was greatly reduced in numbers, some species to the point of extinction. Similarly, Europeans had permanently introduced exotic varieties of plants and animals as well as human diseases alien to North America into practically every environment. "All these limitations we fully realize," the committee wrote by way of confession. "Yet, if [our] goal cannot be fully achieved it can be approached." Since perfection was impossible, the next best alternative was to restore the national parks to at least suggest what North America may have looked like in the precolonial period. "A reasonable illusion of primitive America could be recreated," the scientists maintained, "using the utmost in skill, judgment, and ecologic sensitivity." [8]

With the publication of the Leopold report in 1963, preservation interests eagerly endorsed its substitution of the "illusion of primitive America" for the existing illusions of monumentalism. [9] Much as Americans of the nineteenth century had found comfort in the cultural symbolism of Yosemite, Yellowstone, and the Grand Canyon, so preservationists of the 1960s found reason for hope in the suggestion that some of the ecological damage experienced in the United States—at least in the national parks—might be reversed or undone. Indeed, the lasting significance of the Leopold report lay not in its own romantic images of pristine America but in its guiding principle that the biological management of the national parks was just as important as—if not more so than—the strict protection of their natural features.

Of all the attractions of the national park system none more dramatically symbolized the slow but steady adoption of the principles of biological management than the Giant Sequoias of the High Sierra. Recognition of their cultural symbolism as America's "living antiquity" had led to the protection of scattered groves of the Big Trees as early as the Yosemite Grant of 1864. With their protection against logging and vandalism, however, had not come ecological understanding of their life cycle. The biological sciences were still in their infancy and still basically obsessed with cataloging data rather than viewing it comprehensively. As a result, few but the Native Americans who resided in the High Sierra understood that fires were a common occurrence among the redwood trees. Government wardens of the Sequoia groves instead tried to suppress the ground fires that periodically crept toward the boundaries of the early parks. [10]

Strict protection of the Giant Sequoias against fire seemed in the best interest of their perpetuation as natural monuments. Fire burned other forests; as a result, awareness of the fact that its presence was not universally destructive grew slowly. For example, as late as 1929 Curtis K. Skinner, a respected conservationist, upheld the popular view that fire "without a doubt" was "the greatest threat against the perpetual scenic wealth of our largest National Parks" [italics added]. Throughout the 1880s and 1890s, Skinner wrote, arguing his point, "a fire might rage in the mountain forests for weeks without exciting any more attention than an occasional remark between ranchers concerning the dryness of the weather. Not until the early 1900s, following greater publicity about the needs of the national parks, did the government fully adopt a policy of "increased vigilance and much careful attention to fire-fighting equipment" that the protection of their forests required. [11]

Given the depth of support for Skinner's point of view among the general public, anyone who questioned the wisdom of excluding fire from every forest inevitably drew strong criticism from professional and amateur foresters alike. Still, although they were a distinct minority, proponents of the so-called light burning theory occasionally managed to get a public hearing. [12] One of the first to defend the use of fire as a management tool in the national parks was Captain G. H. G. Gale, commandant of the Fourth U.S. Cavalry, which was assigned to the patrol of Yosemite in 1894. "Examination of this subject," he reported in June to the secretary of the interior, "leads me to believe that the absolute prevention of fires in these mountains will eventually lead to disastrous results." Fire did not appear to be the enemy of the Sierra forest but a presence crucial to the forest's very survival. Annual fires removed the litter of fallen needles and toppled trees on the forest floor, leaving "the ground ready for the next year's growth." Enough younger trees escaped the flames to replace the forest, "and it is not thought," Gale remarked, appealing to the common wisdom of Sierra natives and pioneers, "that the slight heat of the annual fires will appreciably affect the growth or life of well-grown trees. On the other hand," he concluded with a warning, "if the year's droppings are allowed to accumulate they will increase until the resulting heat, when they do burn, will destroy everything before it." [13]

As a proponent of light burning, Captain Gale was little more persuasive than his counterparts in introducing the sustained, systematic use of fire to the national parks. Nor did the establishment of the National Park Service in 1916 lead to any relaxation in the policy of fire suppression. As a result, over the years the superintendents of the respective parks lost sight of the composition of the parks' original forests as younger, competitive vegetation and debris accumulated among the older growth. Finally, scientists during the 1950s turned increasingly to the problems of fire suppression, later publishing their findings in both respected general and professional journals. Not until 1963 and the publication of the Leopold Committee Report, however, did the National Park Service pay serious attention to this new research. Meanwhile, the Park Service was caught up in its Mission 66 program to open the parks to greater numbers of visitors. Thus it was during the 1960s that the need for periodic burning in most of the larger national parks and monuments was recognized as a management necessity. [14]

The Tuolumne and Mariposa groves of Giant Sequoias in Yosemite National Park served as early examples of the consequences of fire suppression. "Two great changes have taken place as a result of fire protection," wrote H. H. Biswell, a professor of forestry with the University of California, in 1961: "First, the more shade-tolerant white fir and incense cedar have developed in dense thickets in the understory of many Big Trees and pines. They greatly add to the fire hazard." Visitors to the park who considered this accumulation "natural" failed "to recognize that fire, too, was a natural and characteristic feature of the environment in earlier times." "The second change of great importance in the Sierra Nevada forests," Biswell said, continuing his pathbreaking article, "is the large increase in debris on the forest floor." Sierra forests "were relatively clean, open, and park-like in earlier times, and could be easily traveled through." After decades of fire suppression, however, most were "so full of dead material and young trees and brush as to be nearly impassable." [15]

By so increasing the fire hazard, such conditions only invited a major conflagration that would wipe out the forest entirely. Fires in the original, primeval forest had been "friendly," limited to the smaller accumulations of "herbs, needles, and leaves on the ground." The Giant Sequoias themselves, "with their asbestos-like bark," easily resisted the low flames and mild heat. In contrast, a modern fire among the redwoods would be enormously destructive, fed by "the development of a solid fuel layer in many places from the tops of the tallest trees to the young saplings and brush and litter on the ground. Is it any wonder," Professor Biswell asked in conclusion, "that the wildfires in such situations are so devastating and difficult to control?" [16]

The significance of these findings aside, additional research during the 1960s and early 1970s further established the importance of fire not only in clearing the Sequoia groves of competitive vegetation, but in actually providing for their existence in the first place. Once again, the observations of a few perceptive individuals writing in the nineteenth century were confirmed. As early as 1878, for example, John Muir wrote that "fire, the great destroyer of Sequoia, also furnishes bare, virgin ground, one of the conditions essential for its growth from seed." [17] Although Muir greatly exaggerated the destructiveness of natural fires, he was nonetheless among the few people prior to 1900 to recognize their significance in the regeneration of Giant Sequoias.

After 1900, fire suppression throughout the High Sierra undermined the advancement of this hypothesis well into mid-century. Finally, both private and government scientists admitted few Sequoia seedlings were growing in the mountains, even in the protected groves. That startling revelation led to the first major studies of the intricacies of the Sequoia forests, studies that widely confirmed that Sequoia seeds rarely germinated unless simultaneously exposed to bare mineral soils in open sunlight. Not only were young Sequoias found to be intolerant of shade and competitive vegetation, but they required fire to burn away the forest litter that prevented their seeds from reaching bare ground in the first place. Historically many of the seedlings had perished in the ground fires that later swept through the groves every few years. The point was that enough of the younger growth had survived the flames to grow up into a new and complete Sequoia forest. In contrast, the suppression of all fires over a period of several decades had choked the open areas of the Sequoia groves with cedar and white fir. Coupled with their own growth, which shaded out the forest floor among the Big Trees, the competitors contributed increasing amounts of needles and fallen branches to the forest litter, simultaneously strangling any Sequoia seedlings that managed to take root in debris as well as darkness. [18]

With the problem in the Sequoia groves so graphically identified, scientists devoted the remainder of their research to finding a practical solution. Among them was John L. Vankat, assistant professor of botany at Miami University in Oxford, Ohio. "Our great challenge," he wrote, summing up the recent findings in the Big Tree groves, "is to return disturbed ecosystems to the point where natural processes may act as primary management agents." In other words, ideally the appearance of the Sierra forest a century ago might be restored, at least in the national parks. As the basis for his conviction, Professor Vankat extensively quoted the Leopold Committee Report of 1963. "When the forty-niners poured over the Sierra Nevada into California, those that kept diaries spoke almost to a man of the wide-spaced columns of mature trees that grew on the lower western slope in gigantic magnificence. The ground was a grass parkland, in springtime carpeted with wildflowers. Deer and bears were abundant." Ground fires were primarily responsible for this pristine environment; with fire suppression began the changes leading to the "dog-hair thicket of young pines, white fir, incense cedar, and mature brush" common along the western slope of the Sierra in 1963. [19]

At least for a government agency, the National Park Service reacted rather swiftly to the findings of the Leopold Committee Report. In September 1967 the Park Service officially reversed its long-standing policy of suppressing all fires in the great majority of its parks. "Fires in vegetation resulting from natural causes are recognized as natural phenomena," read the agency's new policy statement. Accordingly, wherever fires might "be contained within predetermined fire management units" and where burning would "contribute to the accomplishment of approved vegetation and/or wildlife management objectives," natural fires "may be allowed to run their course." [20]

To reemphasize, by "natural" was meant the original appearance of North America at the time of European contact. Strictly interpreted, such a definition obviously had to make allowances for the extensive use of fire by Native Americans. Of course the Park Service had neither the intention nor the means of honoring such authenticity in its forests. Human beings, including Indians, could no longer be recognized as agents of "natural" change. What appeared at first glance to contradict man's original contribution as a factor of biological succession, however, in fact provided park biologists with a resolution to their basic dilemma. Before natural processes could be restored to the national parks as self-perpetuating agents, biologists would have to resort to human intervention yet again. But since Native Americans historically had set fire to forests later protected in the parks, it followed that the adoption of Indian aims and techniques would be consistent with the goal of returning specific ecosystems to the point of self-renewal.

Especially in the Giant Sequoia groves of Yosemite, Sequoia, and Kings Canyon national parks, the unnatural accumulation of dead branches, litter, and competitive vegetation over many decades of protection indicated that any fire, however natural in origin, would nonetheless be highly destructive. In this instance, at least, the biological ends justified any artificial means. The artificial suppression of fires had led to the problem in the first place; clearly, the only way "back to nature," so to speak, was by resorting to an artificial remedy in the interest of eventually recreating the natural rhythms that had been lost. First, the competitive vegetation growing among the Big Trees would have to be cut, stacked by hand, and burned under strict supervision. Afterward, the litter and other accumulated debris on the forest floor might also be burned under carefully monitored conditions when fires were not likely to get out of control. Finally, ground fires of natural origin, obviously from lightning strikes, could again be permitted to burn themselves out in the groves under the watchful eye of park biologists. [21]

As in the past, groves cleared of debris and competitive trees would be subjected only to ground fires, each limited by the scarcity of fuel and the work of previous combustion to lower levels of heat and intensity. The thick, asbestoslike bark of the Giant Sequoias would again protect the mature specimens from harm; equally important, enough of the seedlings would survive the occasional flames to perpetuate the Sequoia forest for centuries to come.

The realization of this scenario, coupled with the ability to restrict controlled burning to the parks proper, spurred its emergence in the 1970s as the most profound and successful response to the principles of biological management outlined in the Leopold Committee Report of 1963. Unlike the committee's other controversial recommendations, such as the reintroduction of natural predators to park environments, allowing fire back into park ecosystems did not depend for its success on the cooperation of other government agencies or private landowners surrounding the preserves. Predators wandering outside park boundaries were almost certain to be shot by farmers, ranchers, and hunters. At least with the proper precautions, fire could be restricted to areas solely under the control of the National Park Service.

As any management philosophy, however, controlled burning also had its detractors, including old-line rangers and concessionaires sensitive to the disappointment of park visitors seeking out the traditional as opposed to the biological. Tourists who had driven hundreds or thousands of miles in search of monumental scenery especially found little to inspire them in mountains obscured by the smoke of smoldering fires, however natural or apparently necessary. [22] Other critics saw another contradiction in allowing natural pollution to hang over the parks, while at the same time objecting to the smoke and dust of distant cities and coal-fired power plants. [23] Manipulation of the environment toward human objectives had long been the basis of American society. Were not the pioneers and their descendents, not merely Native Americans, a natural and therefore legitimate presence in the environment?" Was it not illogical to expect that the environment could be suspended at a fixed point no one living could even remember? Weighed against these deeply philosophical issues, monumentalism in comparison seemed so simple to understand.

The appreciation of natural objects, unlike an intimate awareness of natural processes, required only childlike wonder and a sense of imagination. To be sure, America's historical preoccupation with monumentalism still masked the nation's failure to establish national parks of unquestionable ecological significance. In the final analysis, obtaining national parks of adequate size, not simply experimenting with new management techniques, was the key to the survival of resources other than scenic wonders. In this regard, the ecological issues raised by the Leopold Committee Report and underscored by the First and Second World Conferences on National Parks were still years away from being addressed politically, let alone even partially resolved biologically. [24]