Читать книгу The Men Who United the States: The Amazing Stories of the Explorers, Inventors and Mavericks Who Made America - Simon Winchester, Simon Winchester - Страница 17

Beyond Kansas City the river turns northward, and William Clark offered his views about the kind of terrain that he believed now lay on its western bank. His spelling and grammar were never exemplary: on the evening of June 21, 1804, when he wrote this simple observation, he was probably quite weary:

Supplied with water the Small runs of (which losees themselves in the bottom land) and are covered with a variety of timber such as Oake of different Kinds Blue ash, walnut &c. &c. as far as the Praries, which I am informed lie back from the river at some places near & others a great distance.

The Praries, as he had it, were indeed nearby, and they were of a landscape very different from what had gone before.

Until this point in the journey, the expedition had been quite overwhelmed by trees, by forests, by glades, by copses—by wood. The valleys through which the men traveled and the hills they saw from the water were usually thick with trees. They were burned in some places by Indians, who needed places to conduct their agriculture, but otherwise they seemed totally to carpet the land. Red and white pine forests; oak and chestnut forests, copses of hickory and cottonwood; groves of aspen, birch, maple, and cedar; stands of balsam fir, oak, ash, and walnut—all these and more make their way into the journals of Lewis and Clark, for whom scarcely a day went by without some mention of a tree or a wood or the worrisome absence of woodland where the explorers had believed it should be.

Though Lewis had some scant botanical training, the two were focused primarily on the commercial possibilities of timbering, not forest science per se. Early America ran on wood. People had an urgent need of it for every aspect of life, from fuel to housing, from boatbuilding to the making of crude paper and the construction of that most esteemed emblem of pioneer life, the log cabin. And in those settled parts of the country, wood was abundant. From the white pine forests of Maine to the magnolias of South Carolina and the elms and chestnuts, the cottonwoods and willows of Missouri Territory, the stripling America was bristling with trees.

Except, as William Clark was aware, this suddenly was not so anymore, on the west bank of the upper reaches of the Missouri River. Up on these riverbanks, sometimes close to the river, on other occasions some great distance away, and first seen in the long reaches upstream from where the river makes its directional shift from the west to the north, there appeared glimpses of a landscape now in a state of arboreal undress, much changed from what had gone before.

What Clark glimpsed was a relatively treeless brown-green country, stretching away into a violet horizon that was longer and flatter than any that these hill-born Easterners had ever witnessed or imagined before. It was landscape laid out, flatly undulating, beneath a sky so big it was overwhelming. It was a new kind of prairie, a limitless tableland of grass, a huge grazing-plain, with a wind that soughed near-constantly above the vegetation, the temperature of the drifting air the only clue to the season. Its sky was flecked with mare’s tails of clouds, where lightning could be seen a hundred miles distant and you could watch the black storms chewing their way toward you, the sky suddenly darkening overhead as the squalls arrived and smashed down wafting curtains of hail until the earth was quite white and crunched underfoot, though within moments the reappearing sun then melted it away, steam suddenly began to rise from the grass, and you could almost hear the plants bursting upward in the newly made and richly damp sauna of heat. America was someday to be a united nation, for sure, but in places its newly seen landscape evidently comprised the greatest imaginable differences.

The explorers had reached the eastern edge of that immense, hitherto mostly unseen and uniquely American geographical phenomenon: the Great Plains. Uniquely American, but not unique: there is no shortage of vast midcontinental expanses elsewhere—the Russian steppes, the African veldt, the Argentine pampas, and even some African savannas all offer much the same confluence of flattened topography, pitiless windblown climate, and endlessly unvarying botanical covering. But in America, the Great Plains have been sintered into what is now a cultural, as well as a geographic, entity—a tract of thinly settled grassland of between half a million and a million and a half square miles, depending on the chosen boundaries, a place and an entity that is now an essential component of what America has made of herself, part of the country’s shared triumph and, for many years, part of the narrative of her shared national tragedy, too.

The Great Plains boundaries are fugitive, vague lines that shift from year to year, drift from climate to climate, or wander and wobble like the polar axis. The sudden upsurge of the Rocky Mountains more or less marks their western limit. In the east, where Lewis and Clark became the first confirmed American explorers to encounter them,⁵ their boundary is ill defined at best. Some like to suggest that the Missouri itself provides the line. The land on the river’s eastern side is thick with lush vegetation, the soil so Russian black and damp and rich that some have remarked that it might as well be eaten without any need to pass vegetables through it. The lands on the far side, by contrast, are said to be parched and dusty, their grasses scrawny and patchy, and such meadows as exist having a persistent brown and sun-scorched look about them. But this is all a fancy; scarcely anywhere along the river is the division ever so neat and clear-cut. In fact, seldom can a traveler from the east be entirely sure he has truly entered the plains proper until their presence, after miles of slow and subtle alterations, becomes fully—and to some stunningly, even alarmingly—obvious. And that has little to do with the changing nature of soils or vegetation: it is generally when all the visible world around seems sky and endless curved horizons, where nothing else seems to exist before or behind or on either side but an apparently limitless, wind-hissing emptiness.

Though geology and glacial history have determined the extent and topography of the plains, it is quite simply rainfall—or rather, its lack—that is the real key to their existence. The climate patterns here are so classic that they might be lifted from a textbook. The huge, moisture-laden weather systems that trundle relentlessly eastward across the continent from the Pacific Ocean are forced upward as they pass over the Sierra Nevada and the Rockies; this ascent cools the air, reducing its capacity to hold water. Gravity then insists it fall as rain or snow on the crags below.

What happens next determines the fate of the plains; by the time the weather systems are done with the mountains and swish downward from the heights on their eastward drift, they are exhausted, wrung out, and bone-dry. They roll on for hundreds of airborne miles without immediate purpose, without maturing clouds, and without the will or ability to deposit any further moisture on the grounds below.

The flatlands beyond the Rockies thus lie in a rain shadow, and the vegetation that grows or clings to life within it is peculiar and appropriate to the waterlessness it imposes. And since the vegetation is almost always the key to both animal and human settlement, the role of these flatlands in at least the beginnings of the American story was as fully determined by it as in any other settled corner of the planet. Just as the Inuit and the polar bear inhabit the northern snow country, just as the Tuareg and the camel make their own very different kind of living in the hot African deserts, and just as the San and the Yamana and the Ainu and the Kazakh all adapt to their own unique habitats according to climate, topography, and the local flora and fauna, so too in these prairie parts one finds people and creatures uniquely suited to the conditions: the Comanche and the prairie dog, the Sioux and the rattlesnake, and all of the other Plains Indians—the Blackfoot, the Cheyenne, the Arapaho, and the Crow—together with uncountable millions of the single species of animal that once so dominated and symbolized the grass-covered landscapes here, the American bison.

The plains grasses from which these bison fashion their cud are of very different kinds and appearance, depending largely on the rainfall, the mean temperatures, and the thickness of the soil. Latitude plays its own part, of course; but longitude has the greater role in dividing each from each. Generally speaking, the Great Plains extend between the 95th and 105th meridians—with the midline, the line marking 100 degrees west of Greenwich, denoting by tidy coincidence the approximate limit of twenty inches of rainfall a year: west of the line is drier, true rain-shadow country, while to its east the rainfall becomes ever more abundant and more steady. Altitude plays a part also: because the plains generally slope downward from west to east, from the Rockies to the Missouri River, the western plains are higher, the made-for-movies hardscrabble country of the High Plains, indeed.

This is the great Dust-Bowl-to-be country, rarely much good for agriculture, where otherwise munificent bankers were traditionally reluctant to lend to settlers who were proposing to live there and farm. In this western dry country, the plains are dominated by very short tufted grasses like fescue and needlegrass, and later by hardy imports like crested wheatgrass.

On the 100th meridian itself, in the midplains, there is more of a mix. In what is now Nebraska, say, with its wide, empty farm fields, Willa Cather’s famous “shaggy coat of the prairie” has a pile six feet high at least, made of deep big bluestem, Panicum witchgrass, wild rye, perennial tussock grasses like yellow Indiangrass, and a weave of flowering timothy and blue grama. (The last is a prairie grass that currently displays its own limitations, for it manages at once to be sufficiently abundant to be the official state grass of Colorado and yet is classified as endangered only five hundred miles east in Illinois, whose western counties, if not quite the Great Plains, are very much a part of the tallgrass prairie.)

Lewis and Clark saw all of these grasses—even timothy, the only non-native of the group, which had been introduced from Europe more than a century before and had spread across the nation with astonishing speed. But one plant they would not have seen, despite its now being a near-legendary symbol of the plains—was tumbleweed.

The image of tumbleweed—a ghostly botanical thing looking like a bouffant hairpiece, bouncing steadily across a dusty road before a cold and gritty wind, lodging itself eventually in a barbed-wire fence—is persistent, emblematic, frequently adopted by Hollywood, and generally best viewed on the screen in black-and-white. In most cases, the plant involved is the Russian thistle, Salsola tragus, a pest of a weed, loathed by farmers. The reason Lewis and Clark never reported seeing it is that they arrived too early on the scene by many decades: the vanguard of the tumbleweed invasion came with the accidental importation of thistle seeds in a sack of flax brought to the Dakotas by settlers in the 1870s, six decades after the Corps of Discovery had passed by. It is now just about everywhere, occurring clear across the middle country, from the dusty American West to the lush soils of the Missouri Valley.

It was the eastern tallgrass prairie that Lewis and Clark would have first glimpsed when they made initial contact with the plains during their gentle upriver paddle through what is now Kansas, Nebraska, and the Dakotas. On July 4, for instance, when the party was near Leavenworth, Kansas, Clark wrote:

The Plains of this countrey are covered with a Leek Green Grass, well calculated for the sweetest and most nourishing hay—interspersed with cops of trees. Spreding their lofty branches over Pools Springs or Brooks of fine water. Groops of shrubs covered with the most delicious froot is to be seen in every direction, and nature appears to have exerted herself to butify the Senery by the variety of flours … raised above the Grass, which Strikes and profumes the Sensation, and amuses the mind.

Clark’s “Leek Green Grass” of 1804 is simply today’s big bluestem, the classic of the tall grasses. Its appearance among the scattered copses here hints at the borderline between prairie proper and Great Plains. And Clark is prescient indeed in remarking on its “sweetness” and on the “froot.” This tract of countryside, with its two-foot-deep soil that once gave support to these long grasses, would (once John Deere had perfected his steel plow blade in the 1830s to create a splendid tilth) become America’s present-day granary, with section after section laid to the endless acres of wheat and corn of the richest and most productive grain belt in the world.

But that is the eastern edge, where the soils are rich and fertile. Just six scant weeks and seven hundred miles later, when the expedition had come to what is now Fort Thompson, South Dakota, all had changed. The men had by now passed the mouth of the sand-laden Platte River. Frontiersmen scorned this long and wandering stream, “a mile wide and six inches deep,” as “too thick to drink, too thin to plow,” and held that passing northward over it held a symbolism similar to crossing the equator. The explorers were now in a harsher, drier territory, a wilderness of small braided streams, alkaline flats, and immense buffalo herds, where small cottonwood groves grew only in the deeper stream valleys and where the rich planting soil had given way to rougher grazing land, as Lewis himself noted:

I found the country in every direction for about three miles intersected with deep revenes and steep irregular hills of 100 to 200 feet high; at the tops of these hills the country breaks of as usual into a fine leavel plain extending as far as the eye can reach … [T]he surrounding country had been birnt about a month before and young grass had now sprung up to a hight of 4 Inches presenting the live green of the spring … [T]his scenery already rich pleasing and beautiful, was still hightened by immence herds of Buffaloe deer Elk and Antelopes which we saw on every direction feeding on the hills and plains.

North of the Platte, they had now passed into the true short-grass prairie, and they would have made it farther west, perhaps into the High Plains themselves, had not winter intervened. The first snows came in October. The Missouri was by now substantially shallower, slower moving, and, free of the Platte sands, clearer and purer. As destined by its hydrodynamics it soon started to freeze, and the expedition was obliged to set down its planned winter camp.

By now the expedition had already begun to encounter scatterings of Indians—and in November would meet with one group of Native Americans—and one Native American in particular—who would profoundly change the tempo, the temper, and the reputation of their adventure.