Spread out before me were endless, mountainless plains rolling in all directions. A sea floor without the sea. Cattle, not bison, dotted the prairie on either side of I-70 for much of the 603 miles from Kansas City all the way to Denver.
To begin to appreciate this landscape, you must understand how it came to be. The Rocky Mountains, and even the Appalachians, are easier to admire and grasp than the Great Plains because of the sheer bulk that they send up and the geology that they expose. The Great Plains is a subtler region, or physiographic division, as topographers would tell you, one in need of both a geologic and geographic primer. North America’s geologic contortions imbued the Plains with rich soils. During the Cretaceous Period more than sixty-five million years ago, an immense inland sea, the Western Interior Seaway, sloshed across the region. Into its warm waters sank the organic detritus of fish, amphibians, reptiles, seaweeds, and any land-rooted vegetation that was washed into the sea. Then came the slow ratcheting up of the Rocky Mountains. Geologists continue to puzzle over the exact mechanism that served as the jack, but some speculate that as the oceanic tectonic plate was forced to the east it didn’t sink deep below the North American plate, but took a shallower pitch. As it did, it pushed up the mountains, much as a throw rug scooches up when your foot catches the edge. These riveting mountains, with their steep, canyon-incised flanks, drained rains and snowmelt through the foothills, carrying soils and other vegetative flotsam into rivers that then deposited them on the Plains. As the Cretaceous faded after its seventy-nine-million-year run and transitioned into the Paleogene, and it into the Neogene, the evolution brought glacial episodes with towering rivers of ice bulldozing additional soils and silts into the region. They even remodeled the landscape in places. Streams were pushed into different directions; the mighty Missouri River was shunted roughly 180 degrees, shoved away from its northward flow and sent off to the south.21 All the while, more sediments were carried to the region on the breezes. Mineral-rich grains blasted into the sky by volcanic eruptions rode the winds to the Great Plains from the Great Basin far to the west.
Prehistoric life became imprisoned in this geology. Microscopic plankton, both from flora and fauna, that were buried deep by other layers of sediments and eventually placed under great pressure and heat, turned into oil and natural gas. Dinosaurs turned into fossilized remains. The fossils in the Plains led to the great bone wars of the nineteenth century in places such as southern Wyoming, Colorado, and Nebraska, while the oil and gas continue today to be pulled from below the Plains states for energy. All these geologic perturbations over tens of millions of years produced an incredibly diverse topography. Along with the Missouri, the Milk, Yellowstone, Powder, Cheyenne, Platte, and Dakota rivers carve through the country. So, too, do the Medicine Bow, the Tongue, Arkansas, and Niobrara rivers. Mountains are not a hallmark of the Plains, but a few provide geographic relief, poking up as inland islands above the prairie sea. Along with the Black Hills in today’s South Dakota and Wyoming, there are the Snowy (Big and Little) and Judith Mountains in Montana, as well as the Little Rocky Mountains. But that’s about it.
This is a very big place with a very complex personality. Despite its identifying name, the Great Plains is not self-defining, is not solely a flat, mid-continental placeholder. It climbs in elevation from a reasonable two thousand feet above sea level to a lung-testing—for true flatlanders—seven thousand feet. It embraces the rolling hill country of the Black Hills, the flat prairies with “amber waves of grain” that stir in the breezes that sweep Kansas and the Dakotas, and even the volcanically puckered landscape of eastern New Mexico. Steady erosion for the past five hundred thousand years sculpted the intricate formations found in Badlands and Theodore Roosevelt national parks.
Patches of ponderosa pine forests, buffalo grass and wheat-grass prairie, a mix of bluestem and sandsage prairie, and even oak-hickory forest appear along the eastern edge of the Great Plains. There are expanses of fescue prairie, sections of mesquite and aspen, and some juniper-oak savanna.22 There are draws, washes, gullies, ravines, coulees, arroyos, and canyons. Topographical quirks—cliffs and sinks—were used by Native Americans when it came to hunting bison. Bison herds would be chased by the hunters up to, and then over, these geologic “jumps” to their death. These death traps still stand out today near Chugwater, Wyoming, and on the Sanson Buffalo Jump within Wind Cave National Park in South Dakota. Some outcrops run a mile in length and stand fifty feet tall, and many are still littered with bones.
But the “plains,” the mostly flat sections, are what come to mind when you hear the term uttered. At first glance, this can appear to be a desolate place, especially if it’s winter and a thirty-mph wind blows snow in your face, or if it’s summer and the cloudless sky offers no relief from the hundred-degree heat. Trees are few and far between in the heart of the Plains, too. Instead, you’re greeted by a mix of shortgrass and tallgrass species that are the dominant vegetation. The eastern slash of the Great Plains province that greeted whites three centuries ago gained a bit of height and structure with switchgrass that reached ten feet into the sky, and big bluestem, another prairie grass that rose eight feet above the soil. During the growing season, asters and sunflowers brought more color and some height. Perennial bunchgrasses still today are found in most, if not all, states east of the Rockies. Along with providing forage for bison, pronghorn, and deer on the Plains, the grasses offer cover and nesting habitat for a variety of bird species. Ample rainfall drives the vegetation’s growth. These plant species anchor deep root networks, locking the soil in place while also adding organic matter that encourages farming. On the more arid western half of the Plains grows sagebrush and grama-buffalo grass, the latter a runt compared to switchgrass and big bluestem. While it can struggle to reach ten inches in height, the buffalo grass carpets the prairie with a rich mix of other grasses: western wheatgrass, needlegrass, bunch-grass, and fescues.
Walk the prairie and, if you come after a soft, pattering rain, with the clouds clearing and the sun streaming through, the essence of the landscape rises up. Breathe deeply and fill your lungs with it. The moist air wicks up the pungent scent of sagebrush. As you stride through acres of this woody shrub, your legs brush the branches and their aromatic leaves release an indelible piquant fragrance. If you’re on the far western edge of the Plains, or perhaps in the Black Hills, you also might inhale a sweet, piney bouquet courtesy of ponderosa pines. Along the Plains’ eastern half, there might be a buttery scent, from prairie dropseed. All this vegetation, as it always has, provides food and habitat for pocket gophers, prairie dogs, and prairie chickens. They, in turn, are prey for black-footed ferrets, swift foxes, coyotes, bobcats, ferruginous hawks, golden eagles, and other raptors. Pronghorn antelope—North America’s fastest creature, able to accelerate to fifty-five mph in prairie sprints—and white-tailed deer rove the Plains as well. A mysterious herd of elk drifts through the Red Desert dune fields of southwestern Wyoming.
A well-aged, faded map hanging on a wall in my home locates the many native cultures that historically called the Plains home. People now known as Kickapoo Shawnee, Omaha, and Winnebago lived on the eastern edge where the states of Minnesota, Iowa, and Missouri have been carved out of the country. The Mandan, Brule, Ponka, Yankton, and other Sioux communities made the middle of the Plains home, while the Crow, Gros Ventre, Blackfoot, Shoshone, and Assiniboin peoples claimed the western side. Cheyenne and Arapahoe people also lived on part of this landscape, as did the Minnetarees.
For tens of thousands of years, and still today, the largest animal on this landscape has been the plains bison, known to most people as buffalo. Biologists classify the species as Bison bison, or even Bison bison bison. But the animals were tagged as “buffalo” by the coureurs de bois, the French-Canadian trappers of the seventeenth and early eighteenth centuries. The name stuck with the voyageurs, fur traders who worked for the Hudson Bay Co. and the North West Co. and who called beef boeuf. Whichever name you choose, these animals are impressive to behold. Spend enough time in the Plains states and exploring their landscapes and you’re bound to encounter bison. Growing up in New Jersey, the only bison I encountered were pictured in magazines and sequestered in zoos. Not until my first visit to Yellowstone, in the mid-1980s, did I see bison in the wild. Driving through the park’s Hayden Valley for the first time is an experience you don’t forget, both because of the hundreds of bison and
