Editor's Note: This is the last of a three-part story, appearing in the May 2016 issue of National Geographic magazine. Return to part one, read an abridged version, or find more at natgeo.com/yellowstone.

Dave Hallac stood in his office at the Yellowstone Center for Resources, the park body charged with science and resource management, in a rambling old clapboard building amid the formidable stone structures of Mammoth Hot Springs. A candid man with an oval face and thinning hair, Hallac was serving his last day as chief of the center—and head scientist at Yellowstone Park—before departing to a promotion elsewhere. His office had the look of farewell when I found him there, between final tasks, his shelves and desk already bare, his books and reports and photographs packed into boxes awaiting removal. He closed the door, which was a little unusual on that open-doored corridor, and as we sat amid the boxes, he repeated to me something he had said passingly a couple months earlier, something so arrestingly blunt that I had asked him to elaborate. “I think we’re losing this place,” he said. “Slowly. Incrementally. In a cumulative fashion.” He hesitated. “I call it a sort of creeping crisis.”

Hallac ticked through a list of interrelated concerns, nagging issues in Yellowstone familiar to us both: bison management, elk migration, grizzly bear conservation, private land development in the region surrounding the park, human population growth driving that development, invasive species and their impacts on native species, water use, climate change, and finally the overarching problem that exacerbates all these others—an absence of coordinated, transboundary management. “We go around telling everybody this is the most intact ecosystem in the lower 48,” Hallac said. “Well, if it’s that important, that special, it’s time for us to do a lot better when it comes to protecting it.”

This concern about the broader wholeness of the Yellowstone ecosystem, which others share (though not enough others to leverage vigorous action), is now urgent but has been a long time coming. The word “ecosystem” itself didn’t appear in the 1872 act establishing the park, and probably not, either, in any of the emendations or directives about Yellowstone Park that followed for much of a century. The phrase “Greater Yellowstone Ecosystem” may have been first used in Frank Craighead’s 1979 book Track of the Grizzly, an account of the pathbreaking 12-year field study of bears led by him and his twin brother, John. The Craigheads had absorbed, and stated pointedly, a crucial fact: that Yellowstone’s grizzlies live not only within the park’s boundaries (which are unfenced and, throughout most of the landscape, unmarked) but also across a wider terrain that includes Grand Teton National Park, parts of adjacent national forests, and other surrounding lands.

View Images Jim and Dave Hagenbarth, brothers who own a family ranch in Montana, have dedicated their ranching life to finding new ways to keep agriculture sustainable. Photograph by Erika Larsen

Two years later the superintendent of Yellowstone, a percipient man named John Townsley, used that phrase during a friendly chat with Rick Reese, a young mountaineer and educator. “He told me that to treat Yellowstone Park as a box on a map, with no regard for threats to the park from neighboring national forest lands, was absurd,” Reese later wrote. The park and its animal populations, its plants, its waters, even its thermal features, would be affected by what happened outside that box. Paraphrasing Townsley, Reese wrote that the American people “must be educated about these interrelationships and must begin to think in terms of a ‘Greater Yellowstone Ecosystem.’ ”

Reese served as first president of a new organization, the Greater Yellowstone Coalition, an alliance of individuals and groups dedicated to conserving the broader wholeness of Yellowstone. Soon afterward, in 1984, he published a book graced with pretty photographs but made influential by serious words, titled Greater Yellowstone: The National Park and Adjacent Wildlands. For a while some of the government people resisted this new term, favoring instead “the Greater Yellowstone Area”—a pusillanimous compromise—possibly because “ecosystem” invoked an interconnectedness that ran against bureaucratic compartmentalization and discomfited those with a jealous sense of turf. But in the years since, even they, except the most cautious, have adopted it.

“Yellowstone National Park is not an island,” Reese wrote in that 1984 book, and he was right. But it’s also important to realize that the ecosystem itself is an island in many respects—an ecological island, surrounded by a sea of human impact. It’s isolated landscape. Ravens and eagles may come and go at will, but crossing from the Greater Yellowstone Ecosystem to safe habitat elsewhere is far more problematic for the likes of grizzly bears, elk, and bison. When they step off the island, they generally die.

Who’s in charge of the Greater Yellowstone Ecosystem? Everybody and nobody. There is a deliberative body, the Greater Yellowstone Coordinating Committee, but full membership includes representatives of only the federal agencies (the states, county officials, and private interests participate in subcommittees), and its powers are modest even when its consensus is firm. That’s why Hallac bemoaned the absence of transboundary management in the face of the creeping crisis. “I’m not suggesting in any way that the ecosystem is falling apart,” Hallac told me. “Because it’s not. But it has the potential to. And there are a lot of incremental changes that, I think, are beginning to negatively affect the system.”

After half an hour of such conversation, someone knocked on Hallac’s door and peeked in, reminding him that he was due at his own farewell party. He invited me along, but I didn’t want to intrude, preferring to skulk away and consider what he had said. Park managers come and go, even the best of them, but the problems abide.

View Images Hilary Anderson cuts a classic figure as she rides the range above the Anderson Ranch in the Tom Miner Basin, north of Yellowstone. But her purpose is practical: to deter predators by keeping cattle bunched and by showing a human presence on the land. Photograph by Cory Richards

Bigger Than Itself

The Greater Yellowstone Ecosystem is bigger than any other park complex in the lower 48 states. And size matters. A resonant study published in the journal Nature back in 1987, by a young ecologist named William Newmark, revealed that among 12 national parks and park complexes in the western United States, all except two had lost mammal species in the years since they had been established, but that Greater Yellowstone, as the largest, had lost fewer species than almost all others. Most of those local extinctions had resulted not from direct human persecution—as the wolves of Yellowstone had been persecuted to oblivion—but from the natural processes of extinction characteristic of islands: When habitat is constrained within a limited area, animal populations remain small, and small populations tend to wink out, over time, because of accidental factors such as disease, fire, hard weather, and bad luck. Greater Yellowstone had lost less of its mammal diversity by natural attrition than had small parks such as Zion, Bryce Canyon, and Mount Rainier. Its size, evidently, had served it well.

Newmark’s original work has been challenged in some particulars during the decades since, but its basic conclusion remains sound: Size matters. The size of the Yellowstone complex helped preserve big, fearsome, wide-ranging, combative animals such as the grizzly, each one of which demands a large territory. No other park in the lower 48, apart from Glacier National Park along Montana’s Canadian border, now supports robust populations of the three greatest living North American carnivores—the grizzly, the wolf, the mountain lion—as well as such other predaceous animals as the wolverine, the coyote, the bobcat, and the red fox. Yellowstone is our wildest park south of the border complex that includes Glacier, in part because it’s our biggest.

View Images This band of 1,400 sheep spends the summer grazing season in the Gravelly Range of Montana. They’re tended by three ranchers along with a sheepherder and two Akbash guard dogs. Constant vigilance replaces bullets as a way of deterring predators. Photograph by David Guttenfelder

The other good thing about geographical bigness is that, besides giving space to large predators with broad territorial needs, it usually encompasses habitat diversity as well as sheer space, thereby sheltering a greater variety of creatures at all levels of size, living all modes of life. That truth was reaffirmed to me by an elk hunter one December morning in Jackson Hole, Wyoming.

This hunter had killed an elk on the National Elk Refuge, which is legal by special permit (though, given the name of the place, paradoxical) and with stipulations, such as only limited-range weapons allowed on the South Unit of the refuge. “Limited range” means muzzle-loader or bow and arrow or other old-fashioned weapons, so as to demand more of the hunters and give an element of fair chase. When I spotted this fellow from a nearby road, his dead elk lay on a one-wheeled game cart and with two friends he was rolling it slowly across the bottomland toward his truck. I went striding out to talk with him—committing exactly the sort of nosy intrusion that hunters with freshly killed animals seldom welcome. Once I had introduced myself and explained the basis of my nosiness, he answered my questions genially. His name was Mitch Bock, he said, “like the beer, not the composer.” He lived in Fort Collins, Colorado. He had gotten his elk—a nice cow, six or eight years old, just the sort that the refuge managers hoped to see taken—with a black-powder rifle. He had killed a cow yesterday too, under another permit. That hunt had required a four-hour belly crawl through the soggy meadowland to get near her.

I thanked him for the information and was about to leave. But wait, he said, you’re from National Geographic? Yes. And you all are doing a special issue on Greater Yellowstone? Yes.

“Don’t forget the little boreal toad,” he said. It’s native to Yellowstone, he explained, but like so many amphibians, isn’t doing well in the modern age.

View Images

Parts of One Whole

Everything is connected. That’s the first lesson not just of ecology but also of resource politics. The wolf is connected to the grizzly bear by way of their competition for ungulate prey, especially elk calves and adult elk that have been weakened by winter or the rigors of the autumn rut. Whitebark pine are connected to mountain pine beetles, whose population outbreaks are connected to climate change. Bison are connected to Montana livestock policy by way of a disease, brucellosis, probably brought to America in cattle. Elk are connected to the boreal toad by way of Mitch Bock.

Elk are also connected to cutthroat trout. In this case it’s by way of grizzly predation, taking a bigger toll on elk—some evidence suggests—since the crash of the Yellowstone Lake cutthroat. Aspen trees and willows are connected to wolves and grizzlies by way of the heavier elk predation, which does seem to have helped aspen and willow stands recover (notwithstanding Arthur Middleton’s scorn for the simplistic version of this story) from decades of heavy browsing. Then again, decades of drought and the absence of beaver, whose “habitat engineering” raises the water table, may also have contributed to the historic aspen and willow suppression. Trumpeter swans, rare in Yellowstone, are connected to cutthroat trout by way of bald eagles, which now fly from Yellowstone Lake (where cutthroat, their favored prey, have so declined) to nearby Riddle Lake, where they feed not just on trout but also on the cygnets of nesting swans. Moose are connected to beaver because moose eat willows, but they’re connected also to mule deer by way of a parasitic nematode worm (Elaeophora schneideri), for which mule deer are the usual host. Horseflies carry the worm from deer to deer—or from deer to moose, brokering that connection. The worm is innocuous in mule deer, but in moose it can restrict blood flow to the head, sometimes causing brain damage, blindness, and death. Grizzly bears are connected to corn farmers in Kansas and their decisions on pesticide use by way of army cutworm moths.

View Images A state wildlife manager in Cody, Wyoming, checks on a problem grizzly that’s been tranquilized so it can be relocated away from people. Wyoming and other states around Yellowstone argue that grizzlies have recovered enough for trophy hunting to be allowed. Photograph by David Guttenfelder

View Images Near Livingston, Montana, a rancher shows state wolf biologist Abby Nelson the skull of a wolf he killed. In Montana wolves have now recovered, and hunting them is legal. But hunters are required to bring in skulls so officials can keep tabs on the population numbers and set appropriate hunting quotas. Photograph by David Guttenfelder

The changes that ricochet through these networks of connection, from animal to plant, predator to prey, one level of the food web to another, are known to ecologists as trophic cascades. They are a focus of interest, and disagreement, among scientists who study the wildlife and vegetation of Yellowstone, including Doug Smith and Arthur Middleton. The details of those disagreements become almost Talmudic in complexity, but what’s important to keep in mind is that disturbances have secondary effects, usually unforeseen, and that sometimes those effects are irreversible. Restoring wolves to Yellowstone, for example, does not necessarily fix all the problems that removing wolves from Yellowstone caused.

Such interconnections underscore the truth of a truism: that the Greater Yellowstone Ecosystem is an intricate, interactive compoundment of living creatures, relationships, physical factors, geological circumstances, historical accidents, and biological processes. As an ecosystem, in all its glories and its troubles, its fractured relationships and the consequences of those fractures, it can teach us a lot about how nature works. Its greatest value, its fullest purpose, is not simply to freeze a picturesque place “in the condition that prevailed when the area was first visited by the white man,” as the Leopold Report proposed. Why measure time from the arrival of white men? Ecosystems are continually subject to change, both from human-delivered disturbances (including those caused by indigenous peoples) and from natural ones. The long outline of the Yellowstone Caldera, nicely visible from the top of Mount Washburn, should be enough to remind us of that. In its aboriginal condition 640,000 years ago, the whole place was just a vast smoking hole.

Instead of a smoking hole, we wanted a landscape full of living creatures as well as geysers and canyons, and by a long series of visionary acts, heroic efforts, mistakes, corrections, happy accidents, and good decisions, we have it in 2016. Superintendent Dan Wenk told me that he thinks Yellowstone National Park, for all its problems, might be in better overall shape now than at any time since 1975, the year the grizzly bear’s decline was recognized with federal protection. Hallac, notwithstanding his concern with the creeping crisis, agreed.

Whether the same can be said of the Greater Yellowstone Ecosystem—that it’s in better shape now than for many decades past—is more questionable. Have we vastly improved this great area since the bad old days of commercial poaching and vandalism, governmental neglect, Wild West brigandage, and railroad dreams—or have we already gone a long way toward making it a big, boring suburb with antler-motif doorknobs?

View Images Hilary Zaranek Anderson, shown with her daughters, is a range rider in the Tom Miner Basin area and works on the Anderson Ranch. She is an advocate of having a human presence on the landscape for predator conflict management. Photograph by Erika Larsen

The Greater Yellowstone Ecosystem is a focus of many angers, in part because it contains so many different expectations governed by different interests. Some hunters are angry that there aren’t enough elk. Some ranchers are angry that there are too many. Some wolf lovers are angry that wolves, including those that spend much of their year within Yellowstone Park, now may be hunted or trapped when they roam beyond the park boundaries. Some landowners in Gardiner, Montana, are angry that bison migrate out of the park in winter and into their yards. Some stockmen are angry that migrating bison carry brucellosis, which might be passed to their cows, although not a single case of bison-to-cow transmission has been documented. Some wildlife activists, including those of the Buffalo Field Campaign, are angry that bison from the park, once they migrate out, may be corralled and shipped to slaughter. Some range scientists are angry about overgrazed grasslands in the two parks, resulting from too many bison and elk. Some fishermen are angry about the slaughter of lake trout. Somebody somewhere is probably angry about coyotes. Scarcely a season passes, in the gateway towns of Cody and Jackson and Bozeman, without several public meetings, called by the various agencies, at which people express these angers.

Headline Intro Intro Intro Note or units or whatever Inner headline Inner text. Paragraph with any kind of information commented in the graphic. Inner text. Paragraph with any kind of information commented in the graphic. NG STAFF SOURCE: NATGEO The Impact of Development Since the 1970s the human population in the Greater Yellowstone Ecosystem has boomed, bringing residential and commercial development and new roads. National Park Service Greater Yellowstone Ecosystem 50 mi Roads and railroads 50 km Sources: USGS; Andrew hansen, Montana State university Headline Intro Intro Note or units or whatever Inner headline Inner text. Paragraph with any kind of information commented in the graphic. NG STAFF SOURCE: NATGEO

One such meeting occurred this past December in a hotel conference room at Jackson’s ski resort. Roughly a hundred people crowded in, interested citizens filling rows of chairs, some standing at the back, to hear scientists and managers deliver updates to an interagency committee charged with overseeing the Yellowstone grizzly bear. The atmosphere was tense and adversarial. Many people in the room had fought one another over this issue for decades. The crowd heard Chris Servheen, coordinator of grizzly recovery under the U.S. Fish and Wildlife Service (a position he has held for 35 years), explain that the Yellowstone population had reached its benchmarks—“We consider the bear recovered”—and that his agency soon would propose removing it from the “threatened” list under the Endangered Species Act.

How soon? Very, but indefinite. Delisting means that the states of Wyoming, Montana, and Idaho would be free to issue licenses to hunt grizzlies for the first time since 1975. Frank van Manen, head of an interagency science team that studies the bear, made a dispassionate presentation, which included encouraging data on current grizzly numbers and their distribution throughout the ecosystem, and Servheen discussed those data, all to a largely skeptical crowd. Other scientists and managers took their turns, answering polite questions from the committee, edgier ones from the audience. Toward the end of the afternoon, the floor was opened for public comment from any people who had entered their names on a list.

A man named Reuben Fast Horse, representing the Oglala Sioux Tribe, walked to the podium carrying a small drum. His longish dark hair was pushed back behind his ears. He adjusted the microphone, took off his glasses, and began speaking in Lakota, one of the Sioux dialects. All the white people listened raptly. Occasionally we caught a word—“Europeans.” Fast Horse spoke for three minutes, his speech musical but utterly incomprehensible to most of us, then came to an end point and said: “Don’t worry, the rest will be in English.”

Licenses sold, 2014 170,804* Elk hunting licenses sold Elk kills 93,150 71,890 25,905 25,735 20,600 Wyoming Idaho Montana Total estimated hunting/fishing revenue in Montana $13.1 million in 2014 elk hunting licenses** Estimated 2014 hunting and fishing expenditures (transportation, food, lodging, and equipment) Anglers Hunters $907.8 million $347.9 $137.8 million spent by elk hunters *Includes combination licenses (elk and other game) **In the case of combination licenses, only the elk portion is counted. SOURCES: BRUCE B. ACKERMAN, IDAHO DEPARTMENT OF FISH AND GAME; RON AASHEIM AND NEAL WHITNEY, MONTANA FISH, WILDLIFE & PARKS; RENNY MACKAY, WYOMING GAME AND FISH DEPARTMENT

He read a statement from the president of the tribe, expressing strong opposition by the Oglala Sioux Tribal Council to delisting the grizzly. This statement noted a relationship with the bear “that has existed from time immemorial,” and stressed that the tribe “recognizes the grizzly as a relative, a healer and a teacher of our people, as exemplified in narratives related to our ancestors.” Fast Horse added some words of his own, explaining that his Lakota people “never ate or hunted bear” anymore because, when they originally had, “the skeletal remains looked too human, too close to ourselves.” Then he lifted his drum and his stick, played a strong cadence, and sang a bear song in Lakota.

Imagine you’re a federal manager, like Wenk, seated at the committee table. How do you reconcile that with the metrics of population biology?

Wenk himself has concerns about grizzly delisting—not that the bear population hasn’t robustly recovered, but that the negotiating process doesn’t directly include the National Park Service. That process is “owned by the Fish and Wildlife Service,” he told me later, with park voices left “peripheral.” Will the new management regime weigh the interests of Yellowstone and Grand Teton visitors, who want to see bears, equally with the interests of hunters? Will the sheer economics of bear-watching be duly considered? What happens if a grizzly is wounded in Montana, then comes roaring back across the boundary to suffer its agonies in Yellowstone? What about visitor safety? What about perceptions? Who puts the animal out of its miseries? Who takes the heat? Does that bear count in the hunting limits?

I asked Wenk whether he had gotten satisfactory answers to these questions. He’s a patient man, and a professional. He said: “Not yet.”

View Images Bison and elk share winter ranges in Greater Yellowstone—these are in the National Elk Refuge near Jackson, Wyoming. Both can carry brucellosis, a threat to cattle. But elk are prized as game, whereas thousands of Yellowstone bison have been slaughtered in Montana because some consider them a menace. Photograph by Charlie Hamilton James

Ownership

Wenk’s concern reflects an important truth: that the people who live and work and hunt and fish and hike within the Greater Yellowstone Ecosystem—even people such as Reuben Fast Horse, whose local ancestry goes back millennia—are not the sole possessors of legitimate interest. This is America’s place, and the world’s. Animal lovers at the far reaches of Twitter, people who have never given ten minutes’ thought to grizzly bear conservation, who could never tell you the Lakota word for grizzly nor the bear’s key foods in Yellowstone, are angry at Wenk for ordering the death of the sow that killed Lance Crosby in the summer of 2015. Yellowstone National Park received more than four million visitors that year; Grand Teton National Park received over three million; and having set foot in these places, such visitors feel invested—which is good. As the superintendent of Grand Teton, David Vela, said last July to a group of Latino schoolkids from Jackson who were spending a week in that park as part of an outreach program: “You own this national park. This is part of your heritage as Americans.”

Wes Livingston, the mountain guide, the inveterate hunter and antler collector, the detester of government regulation, the despiser of fatuous liberals and whiny cattlemen, captured much the same spirit one evening in camp up in the Thorofare. Livingston views the park as a single big ranch, managed for desirable animals. In other words: the cultivated wild.

View Images After four decades with the Park Service, Dan Wenk intends to end his career at Yellowstone. “There are few better jobs in civil service than this one,” he says. “Few can ever say they got to look after the well-being of the first national park in the world. This, to me, represents the summit.” Photograph by Erika Larsen

“Who owns this ranch?” I asked.

“We do,” he said.

“Who is ‘we’?”

“The United States of America. The citizens of America, the taxpayers.”

“Does an outfitter in Cody own it more than a wolf hugger in New Jersey?”

“Absolutely not,” Livingston said.

If the wolves provoke varied angers, and the ownership matter is more consensual, other issues stir quiet worries. Agency biologists such as Mark Bruscino worry that the loss of big private ranches to subdivisions will destroy migration routes and winter ranges of public wildlife. Some grizzly bear advocates worry that, with declines in certain major bear foods, delisting and the hunting to follow will doom the Yellowstone grizzly. Others worry that failure to delist the bear, despite its robust recovery, will only further inflame resentment against the grizzly among people with whom it shares habitat and will undermine the Endangered Species Act itself. Bird lovers worry that the trumpeter swan may be eradicated from Yellowstone. Some herpetologists, along with Mitch Bock, worry that an exotic fungus or climate change, or both, may kill off the boreal toad. Wildlife veterinarians worry about the approach of chronic wasting disease, a bizarre affliction similar to mad cow disease, spreading northward toward Greater Yellowstone among mule deer. Tourists worry that, amid the summer crowding, they won’t get a room at Lake Hotel or the Old Faithful Inn. Rangers worry that still another clueless tourist will be gored while taking a selfie in front of a bison. Hallac worries about the crisis creeping across Yellowstone and whether it will slowly ruin the park.

As if that weren’t enough, some people worry (despite reassurances from experts such as Robert Smith) that the Yellowstone supervolcano will explode again soon, incinerating everything and everyone within 200 miles.

Warming Climate Deviation from average annual temperature in the Greater Yellowstone Ecosystem Variation from 1900–2000 average 5°F warmer 3°F cooler 1895 2014 Declining Snowpack Snow’s water equivalent, 30-year averages* 12 inches 1971–2000 1981–2010 O N D J F M A M J *Measured at Northeast Entrance Sources: Tony Chang, Montana State University (PRISM data summary); USDA Snow Telemetry (SNOTEL); Mike Tercek, Walking Shadow Ecology

And me? My concerns focus on the grizzly bear, because I consider this the highest and best purpose of Yellowstone Park and the Greater Yellowstone Ecosystem: to preserve a viable population of that great, terrible animal at the center of the American West into the indefinite future. But I no longer share the extreme pessimism of bear-advocate friends of mine, like Doug Peacock and Dave Mattson, nor their distrust of Kerry Gunther, Mark Bruscino, Chris Servheen, and the other conscientious agency biologists I’ve met, who believe that the bear’s intelligence and flexibility of behavior will keep it robust and numerous despite changes in the landscape that require greater reliance on some different foods.

After all, they say, the grizzly is an omnivore, and three major dietary items—the trout, the pine nuts, the moths—have never been available to all of Yellowstone’s bears every year, nor even to many bears during some years. Whitebark pine nuts come and go in cycles. Spawning cutthroat offered nothing to bears on the west side of Yellowstone, distant from the lake. Likewise with army cutworm moths: Many grizzlies exploit them, but not all grizzlies.

Change may come, these scientists say, but the bear will adapt to the challenge. Dan Wenk is right, though, that the devil could be in the details—that the opaque process of delisting and the return of responsibility to the states contain potential harm to the grizzlies, and to the public’s interest in them, against which there must be guarantees.

Meanwhile we the owners of Yellowstone National Park, and of Grand Teton, and of the national forests and other federal lands of the ecosystem, face some new challenges of our own. The parks need more funding for the impossible work they do; only a fraction of their operating and improvement funds comes from Congress, whereas crucial initiatives such as the Yellowstone Wolf Project are supported by private money, through “friends” organizations such as the Yellowstone Park Foundation. The parks need political support for hard decisions, such as the one that may come when, because of overcrowding, private automobiles are no longer allowed to enter. Sorry: Get on the shuttle.

The most heated wildlife issues, notably grizzly and bison and wolf, need collaborative solutions, not continuing warfare. Passionately dedicated people need to recognize that righteous intransigence is not a strategy; it’s just a satisfying attitude. The various agency members of the Greater Yellowstone Coordinating Committee need to add private groups as partners and to make bold decisions that transcend turf politics. Climate change seems to be hurting Yellowstone—by way of temperature ranges, insect cycles, drought, who knows what else—and we all need to do better on fixing that.

Ha, easier said than done. But if the Yellowstone grizzly bear is expected to adapt, modify its behavior, and cope with new realities, shouldn’t we be expected to do that too?

View Images Yellowstone bison set the pace of traffic over the Highway 89 bridge in Gardiner, Montana, on the park’s northern border. Winter pushes the bison out of the park to lower elevations in search of food, a migration that comes into conflict with agriculture and development. Photograph by Michael Nichols

Epilogue

Any backcountry trip in the Greater Yellowstone Ecosystem is a rare privilege, and mine to the Thorofare with Arthur Middleton and Wes Livingston had moments of pure savor beyond the science. With his elk calves counted, Arthur and I rode still higher on the Thorofare Plateau, above our camp, above the summering elk, until the rising swell of land crested as a narrow ridge at about 10,300 feet. I was amazed that backcountry horses could climb so high and keep their balance on such footing, but I tried not to think about that. Gnarled whitebark pine, much of it dead but some alive, formed a thin windbreak along the ridge. We crossed rocky ground, and meadows enlivened by Indian paintbrush, and then patches of mud, just melted out from beneath last winter’s snow, where in a week or two fresh alpine grasses might grow. The vista around us, through 360 degrees, was epic.

I turned in my saddle, trying to see it all: the Absaroka Range to the northeast, the Trident Plateau just across Thorofare Creek, Yellowstone Lake in the distance beyond that, and even farther, the Gallatin Range. I cranked around. Westward was Two Ocean Plateau, then the Grand Tetons to our southwest, with the Grand itself rising to 13,775 feet, unmistakable in height and profile above the Snake River and Grand Teton National Park. Coming toward us from the south: the highest reaches of the upper Yellowstone River. Arthur pointed across the Castle Creek cirque to where, along a north-facing rim, sizable cornices and couloirs of snow still lingered, shedding their melt to the streams below. This was late July. Look at all that water, he said. It drains to the big river. It grows the grass to feed the elk.

To feed the whole thing, I thought: all the processes, all the players. The photosynthesis and the herbivory and the predation and the competition and the migration and the parasitism and the decomposition, everything downstream, everything that moves into Yellowstone and across it and back out. Seems almost like this is where the ecosystem begins, I said.

“If an ecosystem ‘begins’ anywhere,” Arthur agreed, “this would be it.”

For every beginning in the natural world, there is an ending, and then a beginning again. Does that robust cyclicity hold true even when nature’s wildness is cultivated by people? Maybe. If the cultivation is judicious, humble, and wise. We’re up so high here, atop the Thorofare Plateau, you and I and Arthur Middleton, that a person can almost see the future.

View Images Old Faithful throws a tower of steam into a moonlit sky. Americans rely on the geyser’s steadfast eruptions the way they’ve come to rely on the park itself, as an enduring image of what the continent once was and still can be. Photograph by Michael Nichols