There’s a "tink, tinkle" sound that’s sweet as music to UM archaeologist Doug MacDonald. It’s the sound arrow points, scraping tools and other ancient artifacts make as they emerge from earth sifted through a screen mesh. That "tink, tinkle" means a window has opened to reveal the lives of people who lived as long as 9,000 years ago.
For the past five summers, MacDonald has heard that sweet music frequently in Yellowstone National Park, where he and his students surveyed and evaluated many of the 285 archeological sites surrounding the park’s largest body of water, Yellowstone Lake.
Their work has given insight into how prehistoric Native American hunter-gatherers used the lake, providing evidence about whether they hunted bears, used boats or fished.
"UM has become the go-to institution for Yellowstone archaeology, and we are the only people doing work at Yellowstone Lake," MacDonald says. "That’s a good thing, because there is a lot of archaeology that needs to be done."
Normally, digging holes in America’s first national park violates federal law, but park officials are required by the National Historic Preservation Act to evaluate and protect archeological sites in Yellowstone. The park received a $500,000 grant to complete this work, and that money funds MacDonald and his team.
"What we are doing is important, because many of these sites are disappearing," MacDonald says. "The lake level rises and falls, and many sites are starting to erode away. Before they disappear, park officials want to record them and come up with strategies for which sites they should try to protect, if they can."
MacDonald, an anthropology associate professor, is a leading expert on the prehistory of Big Sky Country — even writing a 2012 book titled "Montana Before History: 11,000 Years of Hunter-Gatherers in the Rockies and the Plains."
He and his students spend up to eight weeks working in the park each summer. Last year, two graduate students and an undergraduate worked with him, and in 2011 there were 10 graduate students on the payroll. Many scientific theses have resulted from the work.
MacDonald says their initial research involved completing the archaeological survey of the lake, including 25 never-examined miles on the eastern shore. Teams of four or six walk slowly along the pebbled beaches or the terraces above the shore carefully scanning for artifacts. They also dig holes about a foot wide and 2 feet deep every 50 feet to identify sites. Some sites were discovered high above the waterline, dating from times when glacial runoff swelled the lake.
"The entire perimeter of the lake is surrounded by archeological sites," he says. "It’s exciting to find these places and fun for our students to find artifacts where it seems like you shouldn’t be able to find anything. We found that most backcountry campsites contain archeological sites — that they are good campsites no matter what era you are from."
At a confirmed site, the team digs up to 20 shovel test pits, as well as two to 20 3-foot-wide square holes. When sifting screens "tink, tinkle" with artifacts, the items are cleaned, processed, photographed, labeled and curated appropriately. All artifact details are entered into database field notes. Then they are removed for study to MacDonald’s UM lab. After two years, they return to Yellowstone and a permanent home at the Heritage and Research Center in Gardiner.
Most finds are stone tools such as arrow and atlatl projectile points for hunting animals, scraping tools for preparing hides and cutting tools for making bone implements. MacDonald’s favorite finds include Cody knives — 9,000-year-old implements named for a Paleo-Indian site near Cody, Wyo.
Many items are obsidian, one of the sharpest substances on Earth, and a place called Obsidian Cliff in Yellowstone was a popular destination for ancient hunter-gatherers to collect what was then a vital commodity. In fact, Obsidian Cliff artifacts dating back 11,000 years have been found at sites outside Yellowstone, so researchers know people visited the Yellowstone Lake area that long ago. So far, the oldest artifacts found within the park date back 9,000 years. (Not much is known about park visitation 12,000 years ago, when the lake area was under an ice sheet at least 100 feet thick during the last ice age.)
The artifacts provide clues to how these prehistoric people lived. For instance, they definitely hunted bears.
"We look for proteins on artifacts we find, and bear is the third-most-common type of protein around Yellowstone Lake behind only deer and rabbit," MacDonald says. "Bear hunting was huge among northern-latitude hunter-gatherers — not just for food but also likely for ceremonial reasons."
Yellowstone Lake contains five major islands, and previous researchers discovered prehistoric archeological sites out there. It was assumed ancient people used boats to reach the islands, which are too far to swim to in a cold high-elevation lake. But MacDonald said their research doesn’t support the use of boats.
"We have no evidence of boat-building tools and no evidence in recent history or prehistory that Native Americans used boats in this area," he says. "So we are looking for other explanations."
He suggests that prehistoric hunters arrived at Yellowstone Lake earlier in the spring than previously thought and walked across the ice to the islands. Bear dens are located in those areas, and bear hunters may have scouted these locations and hunted their quarry as they emerged from hibernation.
MacDonald also notes that sites on the north side of Yellowstone Lake are rich in obsidian from nearby Obsidian Cliff, but such artifacts are much rarer on the south shore of the lake. The falloff implies people walked from place to place, and that it would be fairly rare for people to walk from the north end to the southern end of the lake.
"If they had boats, they were used on a very local basis and weren’t for extended trips," he says. "I think boats would have brought much more Obsidian Cliff obsidian to the south end."
MacDonald also knows from personal experience that using boats on Yellowstone Lake can be treacherous. His research team sometimes uses canoes to move people and gear around the lake, and once he and a grad student were swamped by the choppy waters.
"We only had to paddle a mile, but we only made it about 300 feet," he says. "We tried to make it back to the dock, but we took on water and had to beach in a bunch of trees that had fallen down into the water. It was a sketchy situation. It’s surprising how big the waves get on that lake."
Yellowstone Lake teems with fish, including one of two remaining viable populations of threatened cutthroat trout, so it would be natural to assume prehistoric Natives fished. But MacDonald says their research doesn’t support it.
"We have no evidence of fish protein on any of the stone tools we studied," he said. We also don’t find fish bones, but we hardly find any bones there, because the soil is so acidic. I suppose it’s possible they fished with nets or fish weirs or bone tools, because we wouldn’t find those in the archeological record.
"I really suspect fishing would have been a fallback strategy for them," he says. "The area was so rich in bison, elk, deer, bear and plants like bitterroot and camas that they wouldn’t have needed to fish."
MacDonald says a Shoshone story suggests that either Mother Earth or Coyote stood on a ridge and dumped a basket of fish into Yellowstone Lake to start the fishery. He wonders if the story is a metaphor for human intervention that introduced fish to the lake. Researchers suspect cutthroat trout populated the lake by moving up from the Snake River to the south at some time in the past 11,000 years. MacDonald says his team may study sites south of the lake in future summers to search for use of fishing as a subsistence strategy.
"If ancient people played a role in bringing fish to the lake, that’s pretty cool," he says.
MacDonald and his students often comment about how lucky they are to conduct archeology in one of America’s premier national parks. Once the research team even had a howling conversation with a pack of wolves that lasted nearly an hour, and, so far, they have been spared any bear encounters.
"It’s exciting and humbling to think Yellowstone comes to us to do this work," he says, "and I think we provide them with a good value."
— By Cary Shimek
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