Prairie
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Grasslands National Park, July 9: “In just two days we have seen meadowlarks, horned larks, Sprague’s pipits with their surprising pink feet, phalaropes spinning and dipping like wind-up birds in a dugout, sharp-tailed grouse, nighthawks, western and eastern kingbirds, golden eagles (nestlings and mature), jackrabbits— huge, hallucinatory—cottontails crouching in the shade of large rocks in a prairie dog colony, mule deer, white-tails, pronghorns (bucks, cows with calves), painted lady butterflies, monarchs, showy milkweed in full bloom, prickly pear cactus with waxy yellow flowers, jumping cactus stuck to our dogs, pincushions topped with electric pink blossoms, purple prairie clover, silverleaf psoralea, brown-eyed susans, skeleton weed, blue Missouri milkvetch against bone-white clay, needle-and-thread grass, awned wheatgrass shining in the wind. The cold white glare of a full moon.”
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An Empire of Grass
The key to everything that happens on the prairies lies trampled under our feet. Although grasses may look humble, they are actually versatile and tough, capable of growing under the widest possible range of conditions. Anywhere plants can grow, grasses are likely to be on the scene, whether coexisting with cactuses in a desert, poking up among lichens on the Arctic tundra, or hiding in the leafy understory of a forest. And when circumstances are especially favorable for them—for example, when the climate strikes just the right balance between precipitation and drought—grasses can assert themselves to become the dominant vegetation. (“Dominance,” in this case, refers to the plants that contribute the most living tissue, or biomass, to the ecosystem. As trees to forest, so grasses to grasslands.)
A glance at a map of the world’s major grasslands suggests that these conditions are most likely to occur on a broad, landlocked plain, far from any significant body of water, somewhere near the center of a continental land mass. It is in this semiarid environment—too wet to be a desert and too dry for forest— that grasses gain the upper hand, whether it be on the steppes of central Asia, on the pampas of Argentina, on the savannas of East Africa, or in the broad heartland of North America.
Globally, grasslands are among the largest of the Earth’s terrestrial biomes, or life zones, with a sweep that covers more than a third of the land area of the planet. (At least, that’s the area over which grasses would potentially hold sway if natural conditions were allowed to prevail.) We’re talking some 17.8 million square miles (46 million square kilometers)—almost three times the area of Russia. In North America alone, grasslands naturally extend over about 1.4 million square miles (3.5 million square kilometers), an area larger than many of the world’s major nations.
The first European known to have set foot on this great empire of grass was a soldier and sometime explorer named Francisco Vásquez de Coronado. Dispatched from Mexico City in 1540, he was supposed to investigate rumors about a kingdom called Cibola, somewhere to the north, and to plunder its Seven Cities of Gold. When these glittering mirages turned out to be sun-baked Zuni pueblos in what is now New Mexico, he turned his attention to the uncharted Great Plains, where the fish were as big as horses, the people ate off golden plates, and the king was lulled to sleep at night by a tree full of golden bells. At least that’s what people told him and what he chose to believe. And so off set Coronado, with a party of armed men, in the vague direction of present-day Kansas. In the end, the promised golden city turned out to be a village of grass-thatched huts, where the people lived by hunting bison and growing gardens, each in their season.
Yet despite this disillusionment, Coronado and his party were astonished by what they found along their route. Here lay “a wilderness in which nothing grew, except for very small plants,” but which nonetheless was teeming with million upon million of strange humpbacked cattle. “I found such a quantity of cows [bison],” Coronado reported, “that it is impossible to number them, for while I was journeying through these plains, until I returned to where I first found them, there was not a day that I lost sight of them.” Following along after these apparently endless herds were parties of nomadic hunters— ancestral Lipan Apaches, or Quechero Indians—who dressed in bison-skin clothing (sewn with bison sinew, drawn through a bison-bone awl), slept in bison-hide tipis, and subsisted on a diet of bison blood and bison muscle. Even the grass in this new world was cause for amazement, as it rebounded from the conquistadors’ steps and erased the trace of their presence. In this great round world, all that glittered was grass and an ecosystem of such richness and diversity that it could scarcely be credited.
Overlooked here by the Sweet Grass Hills of northern Montana, the sleek little Milk River takes the measure of the Great Plains, as it flows from southern Alberta into the Missouri River and onward to the Gulf of Mexico.
But think how amazed Coronado would have been if he had somehow been able to sense the true extent and variety of North America’s grasslands. Little did he know that he had set foot on a vast prairie heartland—a continent of grass—that was flanked on every side by smaller islands of grasslands and prairie-to-forest transitions, or savannas. To the north, for instance, beyond his farthest imaginings, lay the Peace River Parklands, a region of rolling grass and poplars that marked the frontier between the Great Plains grasslands and the boreal forest. To the east, the Prairie-and-Oak Transition Zone—a tongue of prairie interspersed with groves of hardwoods—extended to the Great Lakes and beyond, marking the interface between the grasslands and the eastern deciduous forest. To the south, the prairies merged and melted into sultry, soupy marshlands to produce the semitropical vistas of the Western Gulf Coastal Grasslands. And to the west, in the broad valleys of the western Cordillera, lay the California Grasslands—spangled in spring by lupines and yellow-orange poppies—and the arid Palouse Grasslands of the Great Basin. Dominated by scraggly stands of sagebrush and spiky, sparse grasses, the Palouse, or bunchgrass, prairie stretched along the drainage of the Columbia and Snake rivers to intergrade with the shrubby growth of the Montana Valley Grasslands.
And in the center of everything there was the main attraction, the Great Plains Grasslands themselves, a landscape that even today invites wonderment. This truly is big sky country, with horizons that extend from the boreal forests of Alberta, Saskatchewan, and Manitoba to the deserts of the American Southwest and from the foothills of the Rockies to the Mississippi drainage. The numbers speak for themselves. Length: 1,500 miles (2,400 kilometers). Width: between 400 and 700 miles (between 600 and 1,100 kilometers). Vaguely triangular in outline, the region is broadest toward the north and narrows to its apex in the Hill Country of central Texas. Total area: 1 million square miles (2.6 million square kilometers), or roughly 14 percent of the entire land mass of Canada, Alaska, and the Lower Forty-Eight States.
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> DEFINING TERMS
The word “prairie” entered the English language in the 1680s, when fur traders first began edging across the North American continent. Initially, the term was applied to the area just west of the Mississippi River, where the grasses often grew so tall that a man mounted on horseback could not see over them. Later, as the Europeans pushed farther westward, they found themselves in a country of short, spiky plants, quite different in appearance from the Mississippi grasslands. To mark this distinction, the arid grasslands of the western plains were often referred to as “steppe,” a word the explorers borrowed from Russian. The term “prairie,” or “true prairie,” was reserved for the grasslands that the traders knew best, the tall, waving grasses of the eastern plains.
Although biologists continue to find it useful to classify grasslands by height—as short, tall, or mixed—they have dropped the old idea of true prairie. In contemporary usage, the terms “prairie” and “prairies” refer to any expanse of land that is dominated by grass and other nonwoody plants. Prairies, simply put, are grasslands. With the addition of the definite article, “the prairies” also serves as a regional designation for the great grasslands that sprawl across the interior plains of North America.
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p; The geographical terms that are used to define the plains also require clarification. Traditionally, geographers have divided the prairie region into two components: to the west, the Great Plains and to the east, the Central Lowlands. But because there is no clear geographical feature to separate these zones, the boundary between them has never been fixed with precision. On some maps, the dividing line cuts along the 100th meridian; on others, it shifts east to follow the curves of the Missouri River. In either case, the line divides the west from the east, separating prairie from prairie. Several recent sources, however— including the online Atlas of the Great Plains—have erased this artificial division and redrawn the map to show the grasslands of the interior plains as a coherent unit. In this book, the term “Great Plains” refers to the grasslands at the heart of the continent, as shown by the maps.
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The Grand Geographical Tour
But length and breadth are not the only descriptors of the Great Plains. The prairies also have a vertical rise and run that add a whole other dimension of interest. Formed primarily by sediments that washed out of the Rocky Mountains millions of year ago, the landscape slopes away from west to east, stepping down from an elevation of roughly 1 mile (about 1,700 meters) above sea level at the base of the foothills to a few hundred yards (or meters) on the banks of the lower Missouri River. Often, the change happens so gently that you hardly notice it. Who would have imagined, for example, that the drive across Kansas, from west to east, following in Coronado’s path, would be downhill all the way and that you’d lose more than half a mile (one kilometer) in elevation while traversing that seemingly level state?
Overlain on this gently sloping plain are a surprising diversity of landforms. The geography of the Great Plains offers something for every taste, from fantastically sculpted badlands to craggy mountains to some of the flattest expanses of country anywhere on the planet. “I reached some plains so vast, that I did not find their limit anywhere I went,” our old friend Coronado exclaimed in a letter to the king of Spain in 1541, “with no more land marks than if we had been swallowed up by the sea. . . . not a stone, nor bit of rising ground, nor a tree, nor a shrub, nor anything to go by.” The landscape to which he was referring is now known to geographers as the High Plains, an elevated and sometimes spectacularly featureless tableland that extends from Nebraska and Colorado into northern Oklahoma and Texas. An erosional remnant of a high-and-wide landscape that once extended over much of the Great Plains, the region is bounded on three sides by dramatic cliffs, including the upthrusting wall of the Mescalero Escarpment in the west, the tree-clad Pine Ridge Escarpment to the north, and the amazingly convoluted and striated Caprock Escarpment in the east.
Formed by erosion sometime in the last 1 million to 2 million years, the spectacular red sandstone wall of the Caprock Escarpment forms a natural boundary between the High Plains of Texas and the rolling terrain of the Osage Plains to the east. In places, the escarpment towers as much as 1,000 feet (300 meters) above the surrounding country.
To the south of the High Plains lie the limestone hills of the Edwards Plateau, or Texas Hill Country—a world in itself—where the rolling countryside is broken by domed upwellings of rock, deeply cut by streams, and eaten away underground to form a honeycomb of sinkholes and caves. The Edwards Plateau, in turn, is bounded in the south by the terraced ridges and eroded canyons of the Balcones Escarpment, which slashes across Texas at the southern limits of the Great Plains grasslands.
To the northwest of the Edwards Plateau lies the broad Pecos Valley and a landscape of spectacularly eroded caverns, sinkholes, and steep-walled limestone cuts. And north of the Pecos are the shadowed moonscapes of the Raton Section, where mesas capped with lava compete for attention with contorted badlands and the burned-out cones of Capulin Mountain and other long-extinguished volcanoes. From there, it is on to the broad, terraced valleys of the Colorado Piedmont, literally “foot of the mountains,” where the waters of the Arkansas and South Platte rivers have, over millions of years, stripped away layer after layer from the original High Plains surface. (This dramatic, if localized, lowering of the surface explains, for example, why the road heading east out of Denver tracks steadily upward for the first half hour or so, as it climbs out of the South Platte floodplain and onto the surrounding High Plains benches.) The effects of water erosion can also be seen on the rugged Missouri Plateau and the deeply dissected valleys of the Plains Border region.
If water has cut into these landscapes, wind has smoothed them out. For example, the southeastern edge of the Platte River valley is softened by a broad belt of curving, undulating sand dunes that were deposited by dust storms sometime during the Ice Age. Similar formations, shaped by similar forces, are also to be found strewn up and down the drier, western side of the Great Plains, from the Great Sand Hills of southwestern Saskatchewan in the north to the Mescalero Dunes of the Pecos Valley. And right in the middle of the map lies one of the prairies’ little-known natural wonders—the Nebraska Sand Hills, a region of whale-backed, grassy rises and prairie wetlands that, at an area of 24,000 square miles (62,000 square kilometers), ranks as the largest field of sand dunes in the Western Hemisphere. These sandscapes were put in place by the relentless northwest winds that have been coursing across the landscape for millions of years.
With so few barriers to stand in their way, these same winds have had the run of the entire Great Plains region. Although their influence can be seen in many parts of the country—for example, as ridges of windblown silt along both the South Saskatchewan and upper Missouri rivers—their touch is most obvious in the eastern and southern regions of the Great Plains. These include not only areas of the Colorado Piedmont and the High Plains but also the “low plains” to the east, notably the rolling hills of the Plains Border country, the Osage Plains, and the Glaciated Central Lowlands. Much of this sweep of country is blanketed in deep, contoured drifts of fine silt, or loess—pronounced “luss”—another gritty, wind-borne by-product of glaciation. The result is a gently undulating landscape of soft, rolling hills and, in places, extraordinary bluffs, like the delightfully eroded and unexpected Loess Hills of western Iowa.
The northern plains region, by contrast—north and east of the Missouri River, from Alberta to Manitoba and south through the Dakotas—is less apt to be buried in loess, but it nonetheless bears the imprint of the Ice Age. Here the terrain is an unmade bed of glacial rubble, or till, lying exactly where it dropped when the ice sheets retreated from the landscape ten thousand years ago. And protruding above this jumble of knobs and kettles is an assortment of sprawling, flat-topped uplands, including Turtle Mountain, Wood Mountain, and the Cypress Hills, which straddle the boundary between past and present. Like miniature versions of the High Plains, they are the last surviving remnants of an ancient, preglacial landscape that has otherwise been lost to erosion.
Finally, and most surprising of all, are the honest-to-goodness mountains that jut up out of the northern plains, particularly on the unglaciated reach of country south and east of the Missouri River. From the glowering Black Hills to the jagged Crazy Mountains, they stand as a peak experience (if you’ll forgive the pun) for anyone who has been led to believe that the prairies are monotonous.
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> THE MOST TREMENDOUS ROARING
The Corps of Discovery led by Captains Meriwether Lewis and William Clark spent the winter of 1804–5 in the villages of the Mandans and Hidatasa, in what is now central North Dakota. It was likely there that they first heard stories about the ferocious “great white bears,” or plains grizzlies, that had spilled the blood of so many warriors. But when the Corps members met their first bear, at the confluence of the Missouri and Yellowstone rivers the following spring, the kill was surprisingly easy.
“The Indians may well fear this animal equipped as they generally are with their bows and arrows,” Captain Lewis mused in his journal, “but in the hand of skillful rifle men they are by no means as formidable or dangerous
as they have been represented.”
That was April 29, 1805. Six days later, Lewis’s partner, Captain Clark, was singing a different tune. “The river rising & current Strong & in the evening we saw a Brown or Grizzly beare on a sand beech,” he wrote. “I went out with one man Geo Drewyer & killed the bear, which was verry large and a turrible looking animal, which we found very hard to kill we Shot ten Balls into him before we killed him, & 5 of those Balls through his lights. This animal is the largest of the carnivorous kind I ever saw.”
Plains grizzly bear
Lewis described the same encounter in greater detail: “It was the most tremendious looking anamal, and extreemly hard to kill notwithstanding he had five balls through his lungs and five others in various parts he swam more than half the distance across the river to a sandbar, & it was at least twenty minutes before he died; he did not attempt to attack, but fled and made the most tremendous roaring from the moment he was shot . . . . Capt. Clark thought he would weigh 500 lbs. for my part I think the estimate too small by 100 lbs. he measured 8 Feet 7½ inches from the nose to the extremety of the hind feet, 5 F. 10½ Ins. arround the breast.”
Once widely distributed across the Great Plains, grizzlies may have been most common in the major river valleys. They were extirpated from the region by the 1890s or early 1900s.
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