On a cold day in February David Ferguson, an archaeologist from Butte, was inspecting an eroding stream bank in the Helena Valley when something unusual caught his eye. Splinters of bone jutted from the cut bank, small and gleaming in the winter sun.
He knelt for a closer look and recorded his discovery: "Based upon size, the bones appear to be from large to medium-sized mammals... The bone generally exhibits evidence of butchering."
Nearby, Ferguson found a flake of obsidian. It too showed signs of scarring along its sharpest edge, suggesting its use as a cutting tool.
Inadvertently, Ferguson had stumbled upon a prehistoric campsite buried several feet below a hay pasture along Tenmile Creek. Aside from the fragments of bone -- likely from a bison or deer -- Ferguson also found a hearth with heat-shattered stone, and that strange black cutting tool.
It proved an exciting discovery given the Valley's rapid development and changing landscape. Ferguson could not immediately answer who camped here and exactly how long ago that was. As it turns out, there are more questions than answers.
"We know people were in the Helena Valley from 10,000 to 12,000 years ago," Ferguson said. "This site is probably 3,000 years or newer."
It would take more work before Ferguson could accurately date the site, or even render a hypothesis as to who these nomads were. If the campsite were 1,500 years old, as he suspects it is, the nomads may have been early ancestors of the Blackfeet or Shoshone Indians.
Ferguson cautioned that applying ethnicity to a single tool and a fire ring is a slippery slope. However, he does believe the obsidian flake came from Bear Gulch, Idaho. He also believes that the people who stopped here were nomadic hunters, who passed through the Helena Valley on an annual basis following migrating bison herds.
Further excavation and testing at the site could reveal more. Ferguson said pollen samples taken from the buried fire ring could reveal what plants were in bloom when the camp was used. Bone fragments could also suggest an animals' stage of development, helping determine the season. None of the testing is expected any time soon.
"Was this a May occupation or a February occupation?" Ferguson speculated. "Based on what we saw, the site could have intact hearths back off the creek, and they could have more information. Potentially, that site could be extensive."
Significant archeaological discoveries have been uncovered nearby. Montana City, located just south of Helena, rests upon one of the oldest prehistoric sites in the state -- dating back nearly 11,000 years to the Pleistocene Era.
Back then, Ferguson said, nomadic hunters would have traveled to the site to collect chert, a sedimentary rock similar to flint -- prized for making giant spear tips, arrowheads and knives. Nearby, the icy shores of Glacial Lake Great Falls, which spread as far south as Holter Lake, attracted abundant game.
"You have 10,000-odd years of people coming to Montana City to collect that chert," Ferguson said. "The earliest occupants were there, hunting animals now extinct."
Among those animals roamed "bison antiques," the prehistoric version of today's buffalo. Mammoths were common in some areas, along with camels, saber-toothed cats, giant sloths and wild horses.
The Paleo Indians who hunted these creatures could have crossed the ice bridge in the Bearing Straits. However, newer theories suggest they may have migrated from Asia, sailing down the Pacific Coast before wandering inland. However they came, many settled between glacial ice sheets in Montana's temperate valleys.
State Archeaologist Stan Wilmoth of the Montana Historical Society said both theories have their flaws, mainly how a handful of nomads could have populated two continents, giving rise to such cultures as the Incans, the Aztecs, and the archaic Indians of North American Indians.
Montana's oldest known site remains a Clovis site in the Shields Valley north of Livingston. Known as the Anzick Site, the discovery has produced a cache of Clovis projectile points, large flint bicaces, and well-worked bone. Some artifacts are smeared with red ochre -- an Earth paint sacred to Paleo Indians. Two human burials have also been found.
Wilmoth said carbon 14 testing suggests the Anzick Site artifacts date back 11,000 years. But who those people were, or more importantly, who they became, remains open for debate, making later sites like that at Tenmile Creek so important.
"There are a whole range of associated technical changes," Wilmoth said. "They became the ancestors of later Native American people. But putting some kind of tribal identity on them is nearly impossible."
The Paleo Indians living at the end of the Pleistocene Era in Montana adapted to a different world. Massive glaciers that had formed during the era retreated, revealing an altered topography and climate. Sea levels rose and large mammals, like the mammoth, disappeared.
But the people adapted to the changes. As the animals grew smaller, hunters shaped their tools and techniques to the cause. Large Clovis heads used on heavy spears gave way to the Folsom Point -- applied to more precise weapons like the atlatl. The bow and arrow emerged around 2,000 years ago, Wilmoth said.
"They invented stone boiling around 3,000 years ago, allowing the processing of meat that wasn't possible before," Wilmoth said. "When that happened, and how that information spread, are research questions that make that site at Tenmile so important."
Ferguson, who spent his first year in the field as an archaeologist in 1987, said the creeks throughout the Helena Valley were heavily traveled by prehistoric nomads. Over time, most campsites have been obliterated by development. He was somewhat surprised to find the Tenmile site so intact.
"It's kind of unusual to find a stretch that hasn't been disturbed," Ferguson said. "The Tenmile site isn't a dramatic site, but it has enough potential that it may be substantial. It would take more work to determine that."
That work isn't likely to happen soon, according to Diane Tipton with Montana Fish, Wildlife and Parks.
The purpose of the study, Tipton said, was to locate any cultural sites in the area that are more than 50 years old, and to evaluate them for listing on the National Register of Historic Places.
Tipton said FWP hired Ferguson to conduct a site analysis, allowing a local watershed protection group to begin a stream-bank stabilization project, thus improving fish habitat.
"Excavation into the north bank of Tenmile Creek in this location will disturb a cultural deposit that is potentially eligible for the NRHP, pending formal testing," Ferguson wrote the agency in his report.
Ferguson suggested the group's proposal be amended to avoid such excavation. However, planting vegetation could slow erosion and preserve the site for further study, he said.
Reporter Martin Kidston can be reached at 447-4086.