Fossil records suggest that ten million years ago, the migration route of an ancient bird, the distant ancestor of today’s Sandhill crane, cut through the middle of North America, as it still does today (“Maps on Sandhill Crane”). Three million years ago, the land below the cranes’ flight path was dominated by swampy woodland and damp open meadows where stegomastodons, camels, zebralike horses, giant beavers, sabertooth cats, huge ground sloths and other long-extinct species flourished. Thirty thousand years ago, migrating cranes stopped to rest on vast sandy plains chilled by the wind blowing off glaciers just to the south of present-day western Nebraska. The Sandhills hadn’t formed yet. There was no tallgrass prairie. Sandhill cranes of about 15,000 years ago, toward the close of the last ice age, began to encounter Clovis hunters on their annual flight about the same time the climate started to warm, bringing fierce northwesterly winds that molded alluvial deposits into the dunes now covering much of western Nebraska (Hofman).
As the glaciers melted, cranes migrated over a central North America that was rapidly changing. Within a few thousand years, Tundra vegetation established itself then gave way to spruce forests that were eventually replaced by cool mesic hardwood forests (Robertson). Then in an accelerated period of ecological activity 8,000 to 9,000 years ago, three major stresses – climate, grazing and fire – combined to destroy much of the forestland and inhibit its re-growth, creating the perfect opportunity for prairies to spread and thrive. In a brief 500 to 800 years, over 240 million acres of prairie grasslands became a major feature of the landscape beneath the cranes’ annual flight. Sometimes called the “true prairie ,” tallgrass prairie is a complex ecosystem characterized by rich soils laced with the deep roots of sod-forming tallgrasses such as big bluestem, little bluestem, indiangrass and switchgrass, some of which can reach up to 8 or 9 feet tall by fall, the end of the growing season (“tallgrass prairie”).
Following 8,000 years of prairie predominance, the North American interior underwent a swift and amazing transformation between 1830 and 1900. In this span of a single human lifetime (three and a half times the average lifespan of a Sandhill crane) European settlers, aided by John Deere’s steel moldboard plow, steadily transformed the tallgrass prairie to farmland (Drache, 4). Today, less than 1% of the once sprawling tallgrass prairie survives, mostly in scattered remnants found in pioneer cemeteries, restoration projects, along highways and railroad rights-of-way, and on steep bluffs high above rivers (“Tallgrass Prairies”).
The next section of this Discovery Guide takes a closer look at the astonishingly swift changes the American tallgrass prairie underwent during European settlement in the 19th century.
Go To Homesteaders & the Tallgrass Prairie