Technology offers great tools for archaeologists, such as analyzing the residue in ancient ceramic containers to reveal what they contained, or testing proteins on stone artifacts to find what animals were butchered or killed with the tools.
Doug MacDonald, an associate professor of archaeology at the University of Montana, found out the hard way that at least one of these laboratory tests couldn’t be trusted.
MacDonald has worked with a crew of students and representatives from Yellowstone National Park for the previous eight years examining archaeological sites, many of them around the 139 square miles of Yellowstone Lake. The lake is the largest above 7,000 feet in North America.
The university and park crews have recovered more than 24,000 stone tools or pieces of tools from more than 100 sites around the lake. One artifact has been dated back 9,500 years, not long after a huge 3,500-foot deep ice cap finally melted off Yellowstone. “Far and away” most of the excavated sites date from the last 3,000 years, MacDonald said.
Of the tools sent in for testing, the most common proteins found were from elk and deer. Other proteins that showed up in descending order were bear, rabbit, cats such as mountain lion or bobcat, bison, sheep, dog and rodents like squirrels or gophers. None of the tools came back positive with fish proteins, yet early Euro-American accounts talk about plentiful trout in the streams feeding into and out of Yellowstone Lake, once considered the stronghold of native Yellowstone cutthroat trout.
In their study of American Indian use of Yellowstone National Park, Peter Nabokov and Lawrence Loendorf write that fish were second only to bighorn sheep for Shoshone people – called "Sheep Eaters" – known to inhabit the park.
The researchers point to what are believed to be stone net sinkers collected from Yellowstone and housed in the Smithsonian as further evidence of a fishing culture. Similar artifacts have been found at nearby sites, they point out, and excavations near the Gardner River just outside the north boundary of the park recovered fish bones from cooking pits.
But as Yellowstone archaeologist Elaine Hale pointed out to an overflowing crowd at the Livingston Public Library in a Thursday night presentation on the prehistory of Yellowstone Lake with MacDonald, there’s very little detail on where such earlier gathered artifacts were found.
Hale showed a photograph of one net stone, collected by the Bureau of Ethnology in 1884, which has been listed as a sinker.
“Turn it the other way up and I call it wearable art,” Hale said, possibly a pendant on a necklace. “It is the only one I’ve ever seen in the collection of Yellowstone National Park.”
Testing the test
Seeking a definitive answer on whether early visitors ate fish, MacDonald decided to run a test. He used a stone tool to cut up a Yellowstone cutthroat trout and then sent it to the lab that had been testing the other Yellowstone artifacts for animal proteins. He did not inform the lab of what he’d done. The test came back negative for fish proteins.
“Needless to say the lab was shocked,” MacDonald said. “Here we have pretty good evidence that the antiserum wasn’t working.”
But at a cost of $300 a test, it will be a while before the university can afford to have the artifacts properly retested.
Despite the failed tests, MacDonald is fairly convinced that early people weren’t visiting Yellowstone Lake to fish.
“That’s pretty crazy, huh?” he said. “Because when we go to Yellowstone Lake, we go to fish.”
Instead, he believes the main draw was a plentiful supply of nearby plants used for medicine and food. Artifact sites near the lake are concentrated on the northern end, closer to large meadows.
“There are more than 200 different plant species in Yellowstone,” MacDonald pointed out. “Sixty of them are edible or medicinal.
“We know that plants were just as much of a draw as animal. Gathering plants was huge, hugely important.”
Nabokov and Loendorf agree: Hunting and gathering groups in the Great Basin – which extends into Yellowstone – had a diet that consisted of 30 to 70 percent of roots, seeds, nuts and berries.
Still, Nabokov and Loendorf note that the Sheep Eaters were well schooled in capturing fish with weirs or baskets placed in rivers and streams.
“Although the Sheep Eaters were familiar with hooks and lines, they probably caught more fish with dams, weirs and fish baskets traps. Wherever the water channeled through a narrows, at lake inlets or stream shallows, they positioned temporary weirs or brush dams. Driving the fish into them, it was easy to spear or scoop them out with basket nets,” they write.
“It makes perfect sense that the Shoshone and Bannock did fish,” MacDonald said of the two related tribes. He noted that the Blackfeet and Crow tribes may have not, since they recount legends of a large monster in Yellowstone Lake.
But MacDonald said his crew’s excavations have found no weirs and no native fish remains at any lake site. The problem is that the acidic soils around the lake don’t preserve bone well, so small fish bones could have deteriorated.
So he posed the question: “Does the absence of evidence equal the evidence of absence?”
The weirs could easily have been swept away in high water or, since they were made of plant materials, could simply have disintegrated. Or maybe the ancient visitors to Yellowstone Lake utilized tools that archaeologists aren’t recognizing as fishing tools, MacDonald further speculated.
“I don’t think they were fishing that much, but it still remains to be seen,” he said. "We need to dig a little deeper.”