Yellowstone National Park is an approximately rectangular, 2.2-million-acre plot of public land in the northern Rocky Mountains, located in the northwest corner of Wyoming, bordered by Idaho on the southwest, a small strip of Montana to the west, and the bulk of Montana to the north. Founded in 1872, it was the first national park in the world, a pioneering experiment in keeping a beautiful place unaltered against the most fundamental characteristic of human civilization: the alteration of everything we touched.
Located on a volcanic plateau, much of Yellowstone is over seven thousand feet above sea level. The greater part is forested, some in fir and spruce, but mostly in rank upon rank of lodgepole pine. Yet the park is most famous for the smaller portion that is open land: expanses of meadow, sagebrush steppe, and stony ridges dotted with herds of big herbivores—bison, pronghorn antelope, elk, deer, and bighorn sheep— that reflect a mythic sense of what the West looked like before swaths of it were adapted for domestic livestock, alfalfa fields, tree plantations, gas wells, and housing tracts.
The Continental Divide takes an indistinct course across Yellowstone’s volcanic highlands, capriciously assigning drainages to the watersheds of the Pacific and Atlantic oceans. The southern part is drained by the Snake River, which flows into the Columbia, and from there into the Pacific. In the north, east, and west, the Yellowstone, Madison, and Gallatin rivers carry the park’s waters to the Missouri, and thence down the Mississippi to the Gulf of Mexico. At one curious location near the south boundary, Two-Ocean Creek splits into Atlantic Creek and Pacific Creek. “Here a trout twelve inches in length can cross the Continental Divide in safety,” remarked the nineteenth-century fur trapper Osborne Russell.
The name “Yellowstone”—which referred to the Yellowstone River before it was attached to the plateau at the headwaters, or the park— was in circulation among late-eighteenth-century fur trappers in New France as “Roche Jaune.” Anglicized as the River Yellow Stone, the name appeared on an 1805 map dispatched to President Thomas Jefferson by Lewis and Clark. By the late nineteenth century it had become associated with the rich ocher color of the rock in the 1,500-foot-deep Grand Canyon of the Yellowstone in the north-center of the park, but it may have referred originally to the pale yellow sandstone bluffs the river passes downstream, in eastern Montana.
Yellowstone is ringed by mountains—the Absarokas, the Beartooths, the Tetons, and the Madison and Gallatin ranges, but its middle gives an overall impression of flatness. That was the impression Lieutenant Gustavus Doane got of it on a summer day in 1870, as a thirty-year-old Army officer heading up a protective detail of soldiers on an expedition composed of territorial officials. On the twenty-ninth of August that year, Doane ascended a peak north of Yellowstone Lake, and looking south from on top, he noticed an oval-shaped void in the Rocky Mountains thirty by forty-five miles across. Doane was an educated man, and he guessed its origins. “The great basin,” he wrote, “has been formerly one vast crater of a now extinct volcano.”
He was right, except the volcano wasn’t extinct.
Few of history’s contradictions are as striking as the fact that the first really big natural landscape that human beings set out to preserve in perpetuity happened to be sitting on an active volcano that could be expected, within ten years or ten thousand, to vaporize the whole place. Eighteen or more million years ago, a huge plume of molten rock emplaced itself under the western edge of North America, moving inland as the continent was added to by material scraped off the seafloor in the slow-motion collision between the continental and oceanic plates. As the West Coast grew farther away, every once in a while the molten material would force its way to the surface and erupt in a series of what would have been massive catastrophes had there been anyone with real estate interests or insurance policies to compensate for them. Geologists have traced progressively younger deposits of lava and ash from these explosions in a north-bending crescent from northern Nevada across the Snake River Plain through Idaho to northwestern Wyoming. For a couple of million years that material, an underground mass of semi-molten rock 270 miles high, has been parked under Yellowstone. In that time it has produced three gigantic explosions and a series of smaller eruptions and lava flows. The evidence is that the first big one occurred about 2.1 million years ago. The last one, 640,000 years ago, was a thousand times bigger than the 1980 eruption of Mount St. Helens. Geologists have identified volcanic ash from this explosion as far away as Canada, Baja California, and Louisiana.
The United States government considers Yellowstone an active volcano and has set up a Yellowstone Volcano Observatory to keep an eye on it. But the frequency of supervolcano explosions occur in such big and inexact numbers that it is not possible to say exactly where we are on Yellowstone’s schedule. The magma plume is pushing portions of the park upward—at Hayden Valley, about thirty inches in fifty years. Yellowstone Lake has been found to be tilting, inundating trees at one end. The rocks under the park are riven with faults, and the observatory records one thousand to three thousand earthquakes there each year.
Among Indians, and then among trappers and explorers, and later among tourists and scientists, Yellowstone was known for its curiosities and wonders. In a few places its forests contain trees turned to stone. Petrified wood is almost never found standing upright, but at Yellowstone volcanic explosions in the distant past buried standing forests. Then, over millions of years, the trunks of the trees were mineralized, or “petrified.” Later, the soft stone around them eroded away, leaving broken-topped groves of 48 million-year-old extinct sequoia and pine trees with all the fine detail of their bark intact, standing amid living pines and firs.
The most notable effect of the magma chamber beneath Yellowstone is what happens as water seeps down toward it through cracks in the rocks. Yellowstone contains over half the world’s geysers, as well as bubbling mud pots, hissing steam vents, terraced travertine fountains, and pools of hot water painted in garish shades of aqua, yellow, red, and orange by cyanobacteria adapted to temperatures that would kill most other organisms on earth. Clouds of steam rise from the forests and meadows, and in the winter the bare ground of thermal areas provides steamy, high-altitude winter range for bison and elk that normally would have to descend to lower, more protected areas. Standing around amid the fumaroles, bison are sheeted with a hundred pounds of rime and icicles. Portions of the Grand Loop Road running past Old Faithful remain snow-free all winter without plowing. Steam explosions hurl rocks and spit gravel. One geyser that erupts only every few years shoots water three hundred feet in the air.
Human civilization has a simplifying effect on ecology. From the tallgrass prairie of the Great Plains, we made wheat fields. From the rich marshes of Florida, we made tomato fields. Located in one of the more remote areas of the West, developed late, and saved early, Yellowstone was not simplified. In 1972, the park had sixty-six species of mammals, all but one of those present in 1850. Today, with the reintroduction of wolves, it has all of them. Two hundred and eighty-five kinds of birds are seen there. In less than sixty-three air miles, north to south, radically different climates support a range of plant communities. Ten inches of annual precipitation fall on some of the sagebrush hills up north. The Bechler River country in the park’s southwestern corner gets eighty. The wet places are a riot of color in the spring, with spikes of purple monkshood, crimson paintbrush, pink geraniums, yellow arnica, and white bog orchids standing along misty riverbanks patrolled by fish-eating osprey and sandhill cranes. So are the dry places, with yellow balsamroot and electric blue low larkspur. The bloom is followed by a wave of fruition: blueberries, orange umbels of mountain ash, elderberries, chokecherries, and pine nuts.
To early Euro-American visitors, in comparison to New England, Yellowstone certainly looked like a wilderness. But it had been under some kind of human influence for thousands of years before it became a nature-management kindergarten for an otherwise highly advanced civilization that had by then laid a telegraph cable across the bottom of the Atlantic between Ireland and Nova Scotia. In 1959 an eleven-thousand-year-old spear point was discovered during excavation for a new post office in Gardiner, Montana, on the park’s north boundary. About four years later, a ten-thousand-year-old stone projectile point was recovered in southeastern Wyoming, and its minerology traced back to Neolithic toolmakers’ quarries at Yellowstone. Along the shoreline of Yellowstone Lake, archeologists excavated extensive hunting camps aged at 9,300 years before the present. One recent chief archeologist at Yellowstone estimated there are 80,000 archeological sites in the park, of which only about 1,800 have been documented.
On stone tools recovered from the Yellowstone Lake sites, highly sensitive DNA technology found traces of the blood of bighorn sheep, elk, rabbits, and other game. Hunting pressure on Yellowstone wildlife was probably heavier before the 1700s, when the cold snap known as the Little Ice Age and epidemics of infectious disease reduced Indian use of the Yellowstone Plateau.
Above the Grand Loop Road south of Mammoth Hot Springs, a once-famous industrial zone known as Obsidian Cliff glints strangely in the sun. Formed by volcanic flows high in the mineral silica, volcanic glass from Obsidian Cliff was prized by native toolmakers for the production of razor-sharp knives, scrapers, and projectile points. Sourced from different deposits, obsidian looks about the same, but depending on where it comes from, its chemical makeup differs. This mineral fingerprint allows archeologists to trace stone implements back to where they were quarried.
In Ohio, over 1,400 airline miles from Yellowstone, hundreds of objects unearthed at a Hopewell culture site were made of Yellowstone obsidian. At another excavation in Indiana, blades made of Yellowstone obsidian were found over 1,200 straight-line miles from the park. By the eighteenth century the tribes that inherited Hopewell territory were decimated by European diseases. The trade routes by which their obsidian made its way from Yellowstone to the Midwest may have been, in the words of one archeologist, “vectors of death,” transmitting obsidian east and deadly microbes west, ahead of white explorers. Contagion came in waves, first on foot, and later by steam. A smallpox epidemic spread into the northern plains between 1780 and 1782, and another in 1837, aboard a steamboat traveling up the Missouri River to Fort Union. In all, according to Yellowstone historian Paul Schullery, aboriginal North America suffered at least twenty-eight epidemics of smallpox, twelve of measles, six of influenza, and four each of diphtheria, plague, and typhus.
The first non-Indian we know of to visit Yellowstone was the fur trapper John Colter. On his return from service with the Lewis and Clark expedition, he was recruited by the Missouri Fur Trading Company to survey new sources of animal pelts and pass the word among the Blackfeet about the company’s new trading post at Fort Union, later the source of contagion in the 1837 smallpox epidemic. In a remarkable five-hundred-mile solo trek in 1807 and 1808, Colter passed through Yellowstone. After 1826 the area was visited regularly during the fur trade, and according to accounts from that time, the Blackfeet, Crow, Sheepeaters, Bannock, and other Shoshone groups were sharing the area for hunting, fishing, and quarrying obsidian.
After microbes did their work, the founding of the national park took place against a backdrop of military mop-up operations. In 1877, some six hundred Nez Perce men, women, and children passed through Yellowstone, fleeing a massacre by Army cavalry with orders to kill them or force them onto a reservation. In a strange juxtaposition of Yellowstone’s past and its ecotourism future, the Nez Perce encountered park visitors on camping excursions whom they took as hostages and, in some cases, shot. The following year the US Army campaigned against the Bannock in the region, and in 1879 against the Sheepeaters in what is now the Frank Church–River of No Return Wilderness, to the west in central Idaho.
When this dark chapter in American history was over, by the twentieth century, visitors from Chicago or Great Falls could stroll up a Yellowstone trail and imagine themselves as the first humans in a wilderness that had never been entirely free of people since the end of the last ice age. Because Euro-Americans didn’t witness the effects of Indian hunting until after Indian populations had been reduced by infectious disease, we can only conjecture about how they functioned in concert with cougars, bears, wolves, and coyotes in regulating the number of prey species, such as bighorn sheep, deer, elk, bison, moose, and antelope.
The Lamar Valley, an elongated basin of wide-open grassland and sage steppes in the northeast corner of Yellowstone, has long been known as one of the two or three best places in the park to observe wild animals. For most of the twentieth century the valley harbored America’s largest herd of wintering elk. The two-lane road from park headquarters to the Northeast Entrance, which traverses the base of the hills on the valley’s north side, is the only road open through Yellowstone in the winter. Not many years ago, when the elk came down from the high country with the first snows, people would drive out to the Lamar Valley to marvel at the mass of blondish-brown, furry backs shining in the winter light, the forest of antlers, and the sparkly dust of snow as the elk pawed around for something to eat. The northern elk herd, as they were called, were seen as one of the last great wild spectacles of North America, an intimation of how things had once been, before they were altered. Or so people thought at the time.
A short piece southeast along the road through the Lamar Valley from the cluster of log buildings known as the Buffalo Ranch, there is a paved turnout where visitors get out of their cars with their binoculars and spotting scopes to observe herds of bison and pronghorn antelope. From 1989 to 2013, a Park Service educational placard stood facing the road there at waist level. The text was laid out over a large photograph of what you would see on an average summer day from there: grasslands, a row of old cottonwood trees, and wild animals. The text explained that the Lamar Valley supported “. . . a remnant of the vast wildlife herds that once roamed North America” above which was the placard’s title, in large letters: AN AMERICAN EDEN.
And so it seemed to any visitor who didn’t know the place’s history. To anyone who did, the Lamar Valley bore less resemblance to Eden than to the Civil War battlefields the Park Service takes care of back east. For decades it was probably the most scientifically contested piece of ground in America. The fight there was about how much scientists ought to manipulate and control nature in order to preserve it.
Arguments are rooted in uncertainty. There is little controversy about things we know for certain. In order to understand the disagreement that began at the Lamar Valley and spread to the rest of Yellowstone we must go back to the early nineteenth century, when what was about to happen to the western United States could be compared to the loss of knowledge of the ancient world when the Library of Alexandria burned to the ground in 48 BCE. But in this case, the “library” that was to be burned—and cut down, dug up, shot out, and sold off—was the information that could have been gathered, had there been anyone with today’s ecological skills to do it, about what nature was and how it had worked before it was altered.
