Trackhoes and Trowels: How road builders and archaeologists are teaming up in Nine Mile Canyon
It's all excavation. The difference is you guys use trackhoes and we use trowels." That's how archaeologist Jody Patterson explained the contrasting digs going on in Nine Mile Canyon to a few civil engineers who dropped by for an update.
Patterson, who earned his Ph.D. in archaeology, is principal investigator for Montgomery Archeological Consultants. This is the Moab-based firm that is providing the monitoring and training for the road construction team. About 150 people have been trained in spotting and protecting the sensitive sites along the 36-mile route.
That number includes engineers from Jones & DeMille Engineering and workers of construction contractor W. W. Clyde. It also includes Carbon County engineering and road department employees. County Engineer Curtis Page carries the card documenting his course completion in his wallet.
All this cultural sensitivity training has paid off. During the past year of construction, workers and monitors have found nine previously undiscovered sites holding clues about the ancient Fremont Indians who inhabited the canyon long before Columbus "discovered" America.
A tenth discovery turned out to be nothing more than a burned root. Better to be safe than sorry, though. One of the telltale signs of an old hearth or pit house is charcoal or soot on the rocks.
If not for the excavation and earth moving during construction, some of these sites might have gone undiscovered forever. One such find goes by the prosaic designation of 42Dc3053.
It is classed as a habitation but it is more than that. It is one pit house built atop another. Patterson said both structures were buried under almost ten feet of earth.When the site was unexpectedly unearthed, construction stopped and science began.
The archaeological team staked out the area. An orange lattice fence - a ubiquitous sight in the canyon these days - was put up to notify equipment operators that this was a place to be avoided.
Montgomery researchers then began the patient, meticulous task of archaeological digging. In addition to trowels, they use whisk brooms to remove soil from the ruins.
To make sure every scrap of evidence is collected, they scoop the soil into screen box, shake it to filter out the the sand and dust, and then examine the small bits and pieces left in the box to find things of significance.
They have recovered crude stone implements and flakes of flint left over from the sharpening process; pointed wooden or bone tools; and tiny flat wooden beads that look like washers. One item that didn't require sifting was a metate (grinding stone) that weighed about 25 pounds.
"Too bad it was found with the bowl side up," commented Patterson. "If if was face down, we might have been able to scan it for pollen."
The USU Eastern Prehistoric Museum is the designated repository for the finds in Nine Mile.
One find in particular excited Patterson. He lifted a plastic blanket from a corner of the dig that has been covering something. The visitors then could see...some black stuff.
"It's a woven grass and cedar bark floor mat," he explained. If you got close enough, you could see the fibers. The mat apparently continues further into the house, not yet uncovered from the few inches of dirt remaining.
There's a question about this whole process, though, and that is if these long-hidden sites are being destroyed by the very equipment that finds them.
"Archaeology is destructive," Patterson replied, "but we are recovering data as we are destroying."
The very act of searching involves moving things around, and that changes things.
As for sites like the double pit house, "There was no indication that they were even here."
'A paradigm shift'
Perhaps someday the earth covering the house would have eroded away, but the forces of erosion would also wash away and scatter the artifacts.
That scattering would remove them from their context, making them useless from a scientific perspective.
The information being gathered from these unanticipated finds is going to serve an important purpose.
"Basically, we're in the midst of having a paradigm shift. We didn't know there could be a farming site deep in an alluvial fan. Now we'll know better where to look," Patterson said.
Speaking of alluvial fans, it might be helpful to explain what they are. They are deposits at the ends of streams, where silt-laden water from canyons or gullies fans out and slows down.
That slow, shallow water drops its load of dirt.
Building one pit house on top of another would indicate the earlier one had been buried during runoff, or several years of runoff, so a second one was built in the same spot.
Patterson thinks that the fans could have been the best place for small farms to grow corn. The soil is already wet after having been soaked in the stream, so little if any irrigation would be needed.
One project has been to calculate the volume of all the known Fremont granaries in the area, then figure out how much corn and grain would fit in them. Then it's a matter of determining the crop yields that could be expected from farming the fans in the canyon and its tributaries.
So far it looks like the harvest from the fans could have filled the granaries.
Still to be determined is whether the ancient residents were year-round or seasonal occupants. Why build a house on a known flood plain? It could be that the Fremont simply wanted to be close to their gardens from planting to harvest.
They could could have come and gone, allowing a recently harvested field to lay fallow for a few years while pursuing a hunting-gathering lifestyle in the off season.
The protection of what has been called the "world's longest outdoor art gallery" does not come cheap.
Jones & DeMille engineer Brian Barton provides numbers showing that $930,000 has been spent so far, tallied basically at the beginning of the second year's construction. That's about one-eighth of all the money spent on the road to date.
Much of the money has been spent on dust suppression and monitoring, coating the roads with lignin sulfonate to bind dust particles together and keep them from going airborne and coating the rock paintings and carvings.
Other measures included in the figure are cultural monitoring and mitigation and coordination with special interest groups. There is daily monitoring of all earth-disturbing activities.
One group that is constantly updated on construction and mitigation is the Nine Mile Road Cooperative Board. It's made up of representatives from the Carbon and Duchesne county commissions, the Bureau of Land Management, industry (generally meaning Bill Barrett Corp.) and the Nine Mile Coalition.
The objective of the board is to get all interests together at the same table to talk and listen to each other.
On a road tour through the project area, Barton noted two of the modifications to the project plan that have come about because of the discussions.
First is a re-routing of the road to avoid disturbing a midden - a prehistoric junk pile that is densely packed with archaeological evidence.
"The road was moved 15 feet away and elevated two feet to protect it," said Barton.
Next is a concrete blanket covering the side of a hill near the famous Cottonwood Panel at the east end of the project. Atop that hill are the remnants of the Cottonwood Village, a Fremont settlement.
The toe of the hill had to be cut off to accommodate the road because the canyon is so narrow at this point. That could have accelerated erosion of the soft earth.
The the road builders erected and fastened a steel framework to the hillside, then coated it concrete.
"That was an $80,000 job," noted Barton.