A race to rescue frozen artefacts
As the world warms up, archaeologists are discovering that some of the most fascinating glimpses of prehistoric life are melting from ice.
Ice crystals landed on my face, falling from the ceiling of the tent and shocking me awake in a frozen flash. Through my many layers of fleece, I heard a faint snuffling noise. I unzipped my sleeping bag in a daze and sat up, with one eye on my canister of bear spray and one ear straining to listen.
All I heard was the rapids from the nearby creek and a welcoming whinny from one of our horses grazing in the alpine meadow outside Yellowstone National Park. Just then, I heard the fresh sound of sticks snapping as someone – or something – crept by. Opening the tent flap, I stared out across the foggy meadow below the Absaroka Mountains and then down at the ground, where a track from a large wolf was freshly imprinted in the soil, mere inches from where I had been sleeping.
View image of An alpine archaeologist looks out over the Teton Range in Wyoming (Credit: Credit: Matt Stirn)
Over at the campfire, a colleague mentioned that a pack of four wolves had just been sniffing the outside of my tent. “It was only the mountains saying good morning,” she said, placing the kettle back onto the embers. “With a visit like that, we’re bound to have an extraordinary day.”
In my 15 years of working with scientists in the US’ Rocky Mountains, I’ve come face to face with grizzly bears, escaped forest fires, swum across flooding rivers while holding onto horses and discovered prehistoric villages. But I’ve never considered a tent-side wolf visit to be a blessing. Yet, as the red light of the sun illuminated the slope above us, I looked up at the glistening snowfields and wondered which ancient, frozen stories the mountains would reveal today.
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As an alpine archaeologist, I study how past cultures lived at high altitudes and snowy environments above the tree line. Visitors, eyes squinting and necks straining, often describe the alpine landscape’s wind-whipped crags and icy gorges as harsh and intimidating. But growing up at the foot of Wyoming’s Teton Range in the heart of the Rockies, I have always felt at home here. In fact, 3,000m is where I feel the most alive. Yet, it wasn’t until I started exploring my backyard from a different perspective that I realised the wilderness holds a vault of forgotten and untold stories that intertwine people and nature.
View image of A team of alpine archaeologists hikes towards base camp in the Teton Range, Wyoming (Credit: Credit: Matt Stirn)
As a teenager, I spent my summers guiding mountaineering trips throughout Wyoming. During one particular trip into the Wind River Range, I found an arrowhead next to our camp, and the notion that our tents were pitched in the exact spot where someone else had camped 2,000 years prior made me wonder why mountains have always attracted mankind. Upon starting college that autumn, I tried to research the history of Wyoming’s mountains, but could only find one reference in an old archaeological journal stating, “the high country was too harsh to support prehistoric people”.
Several months later, I discovered that an archaeologist from Wyoming named Dr Richard Adams had just unearthed an entire prehistoric village only a few miles away from where I had found the arrowhead. I contacted him and he invited me to join him on a project to excavate the village he had found. Adams showed me that the mountains held ancient secrets waiting to be uncovered, so I traded in my climbing rope for a trowel and began an exhilarating new career in search of our hidden past.
I now direct projects in the mountains of North America ranging from archaeological digs to satellite searches to locate prehistoric villages. It has been a fascinating adventure, and humbling to think it all began with a chance discovery as a 17-year-old.
View image of An ancient piece of wood emerges from a thawing ice patch in the Wyoming mountains (Credit: Credit: Matt Stirn)
Because many archaeologists have long considered alpine environments too harsh to have supported ancient people, most mountains remain vastly unexplored. However, for those who have begun to work among the towering peaks across the globe, high elevations are an exciting terra incognita that are just beginning to be understood.
In summer, my colleagues and I trek deep into the Rocky Mountains, from the glacier-carved peaks of Wyoming to the high meadows of Colorado, in search of undiscovered villages, hunting structures, stone quarries and other evidence of life from about 13000BC (when humans are believed to have first arrived in North America) through the present. But unlike most archaeology, there is one thing that is particularly unique about our work: the clues we find aren’t always buried in the soil; sometimes they’re trapped under the ice.
In mountain ranges across the world, ancient people used snowfields, glaciers and ice patches to hunt, store food and use as bridges over otherwise impenetrable terrain. Just like modern-day trekkers, these ancient hikers occasionally dropped personal items, which, over time, became trapped and preserved in the ice. While we unearth many non-biodegradable, prehistoric stone artefacts, our most fascinating discoveries are so-called “ice patch artefacts” like arrow shafts and twine made of wood, leather and other organic material that would have otherwise decomposed if not entombed in a natural freezer.
These incredibly rare materials not only offer a glimpse into ancient life we rarely get to see, but also hold invaluable clues about everything from the migration patterns of early humans to prehistoric cuisine to how the environment and weather has changed over the millennia.
While ice patches and glaciers possess a trove of scientific information, they are in imminent danger of being lost forever. Because of increasing global temperatures, mountain ice is melting at an unprecedented rate, and these frozen perishable artefacts that have remained preserved for thousands of years are quickly thawing and disintegrating. As a result, searching for ice patch artefacts is both an exciting opportunity, and a desperate race against time.
In 2007, Dr Craig Lee from Montana State University discovered an oddly shaped stick melting out of an ice patch at 3,200m in northern Wyoming. After closer analysis, Lee realised that the stick was, in fact, a dart from a throwing spear crafted an astounding 10,300 years ago. To date, it’s the oldest frozen artefact found anywhere in the world. Lee’s unexpected discovery underscored the urgency of recovering these thawing artefacts and has prompted an intensified search to rescue them throughout the Rocky Mountains.
View image of Fragments of an American bison skeleton that had melted out of the mountain ice, suggesting they once lived in higher altitudes (Credit: Credit: Matt Stirn)
As more archaeologists have ventured into the North American alpine tundra in the past decade, artefacts ranging from 1,300-year-old arrows to woven wicker baskets to wooden bows have been unearthed, revealing some surprising discoveries. Wood analysis demonstrated that prehistoric groups favoured certain tree species for their arrows; frozen pollen offered detailed paleo-climatic records indicating that tree lines used to be much higher; and seeds from thawing scat showed that, unlike today, American bison once thrived above 3,000m. A vault of new information has become unlocked, but that door will not remain open forever. Given the sheer number of ice patches and their remote locations, we will never be able to reach them all in time.
In an age where computers and satellites have replaced machetes and pith helmets, many explorers lament that the age of discovery is over. Yet our expeditions echo the approaches of many of North America’s early inhabitants. Because we venture deep into the mountains in some of the most remote locations in the continental US, we need to rely on horses and cowboys to transport gear and food up the alpine slopes. We set up backcountry camps high above turquoise lakes, harvest edible plants from nearby meadows, roast fresh game like elk or bighorn sheep over an open fire and sleep under a sea of stars. In many ways, travelling and living in the footsteps of the ancient people we’re studying helps us to better understand them.
View image of After a long day in the mountains, two researchers relax next to a campfire (Credit: Credit: Matt Stirn)
We never know which ice patches may reveal prehistoric items, so our days are spent hiking over passes and exploring ridges to search for clues. When we spot artefacts or animal bones protruding from the melting summer ice, we carefully extract them and wrap them in gauze and plastic to ensure a safe journey on the horse ride home. Back at the lab, we photograph, radiocarbon date and identify the species of each artefact before returning it to a deep-freeze state at a museum or university repository. The thrill of discovering a prehistoric stone bowl or 8,000-year-old spearhead in the field is always exhilarating. But it’s in the laboratory that the fascinating stories of these artefacts begins to appear, such as what meals were prepared in the vessel and where ancient people travelled to acquire the stone for their weapon.
Despite the countless blisters, frosty evenings and hordes of mosquitos, I’m grateful to call the mountains my office. Every discovery of a whittled stick or a butchered bone at the ice’s edge reminds me of the small role I play in preserving the mountains’ and humanity’s shared history.
As a young climber, I spent countless days exploring the towering peaks of the Tetons and would have told you that I knew everything about them. But during the past 15 years, I’ve learned that whether you’re in the most familiar or foreign of settings, there is always more to discover about a place. Everywhere in the world has a fascinating and new story to tell, if we only seek to uncover it.
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