Driving into Mullen Nebraska, in the heart of the Sandhills, the wind howled outside our Suburban as the sun set over a vast landscape. The few hundred residents of the biggest little town in Hooker County pride themselves on hospitality—a hospitality that the weariest of travelers would certainly have come to love, providing a brief reprieve from powerful gusts. A mile outside of town in any direction, the wind is unforgiving. Here, despite relentless wind, sporadic climate and weather, cattle and bison graze over the endless stretches of hills formed over thousands of years of shifting sands. Today, the Sandhills are relatively stationary because deep grass root structures hold the sand in place. But that wasn’t always the case, and this land tells a story from the past: a story of an unforgiving environment and a people forced to adapt to a changing climate.
Professor Matt Douglass and a team of graduate and undergraduate students from the University of Nebraska – Lincoln’s anthropology department traveled here for a week of field school in archeology. The team will collect sediment samples under the top layer of grass or, as is the case in some locations, sediment that has been exposed in blowouts, where a combination of wind and water has eroded topsoil and grass, leaving an indention in the land. They hoped to discover artifacts, telling of the Sandhills’ first farmers, as well as collect samples that will help date the last major climatic event in the region, estimated to be between 900 and 1350 AD, known as the Medieval Warming Period. During this period, temperatures were 1°C (1.8°F) higher, causing the Sandhills to mobilize, forcing an exodus of early residents, marked by a break in the archeological record.
We caught up with Douglass and his team on their fourth day in the field. The previous few had been plagued by unpleasant weather setting their work behind schedule. Douglass found us at our motel, weary from a day of driving. His hair was matted and wind swept, his skin a leathery tan; he had spent many years outdoors, including the last several nights, vulnerable to the harsh wind and the typical Nebraska early summer thunderstorms. This year, though, was exceptional. Four of the last five days saw intense fronts move through, bringing relentless rain and heavy winds, one of which set state records for recorded daily rainfall.
Work continued the following morning north of town on the North Loup River near our permanent camera location. Heavy winds pelted sand at our faces and equipment, preventing much from getting done. The subsequent day was more profitable east of Mullen on the Kelso site, the most extensively excavated woodland site in the Sandhills. Tucked inside a treed valley that guides the Middle Loup River around the base of each hill towering above us, the Kelso site was a beautiful location for the team to dig into the landscape, searching for answers.
The Sandhills are characterized by large stabilized sand dunes (some exceeding 100 meters in height), mixed-grass and short grass prairie grazed by beef cattle, and the expansive Ogallala Aquifer, which is deepest under the region. Most of the water flowing south-east out of the Sandhills is spring fed, where the high water table of the aquifer bubbles to the surface. In the valleys between dunes, the water table visibly rises, filling the valley with water. These features make the Sandhills a unique landscape, vulnerable to intensive grazing and drought, as evidenced in the past.
The team was composed of graduate anthropology students like Nora Greiman, four undergraduate students taking the anthropology department’s offered summer field school archeology course, and on this day, a group of on-lookers and volunteers from the UNL School of Natural Resources. Nora’s research guided the day’s events, beginning each morning at camp. At Kelso, the excavation site was within walking distance of camp in a wooded valley along the Middle Loup River.
After digging a meter into the sandy soils, the team excavated a shelf almost a foot higher than the depth of the hole. Graduate student Mike Chodoronek sharpened his carving tool and gently hammered a tube into the shelf’s soil, extracting an intact core. The sample contained soil ranging from 950 to 1350 years ago.
The second location on the Kelso site contained surface artifacts that help the team determine the ideal location for excavation. The team scattered around the site, searching for bone, pottery shards, and other exposed artifacts. The excavation began where there is the greatest concentration of surface artifacts.
The field school researchers and students exercised methods used to collect the archeological record and investigate the impacts of a changing climate on prehistoric populations. Their work that day helps to tell the story of the past, and, I would suggest, helps to tell the story of today. The thread that binds this story over the centuries is something fundamental: water.
It was drought over a thousand years ago that brought us there that day. And it is water that makes life possible in the Sandhills today.