Archaeologists unearthing treasures at A-LP site
By Gail Binkly
Nearly everything involving Animas-La Plata is controversial.
Even though the now-$500 million project to construct an off-stream reservoir for water siphoned from the Animas River is under construction after decades of debate, its supporters and foes still argue its merits as bitterly as ever.
But in the center of the controversy – literally – archaeologists are working serenely, untouched by the swirling arguments. They are taking advantage of a rare opportunity to conduct a large-scale excavation of Ancestral Puebloan sites southeast of Durango before those sites are submerged beneath 120,000 acre-feet of water.
And they’re making discoveries that have them intrigued, puzzled, and – as is always the way with archaeologists – seeking more information.
Some unusual structures on a hill are of particular interest, said Jim Potter of SWCA Environmental Consultants, the archaeological firm hired by the Ute Mountain Utes, who are constructing A-LP. He is the lead archaeologist for the four-year study being conducted on the area that will be affected by the project.
“We found some really interesting architecture that we didn’t expect up on Sacred Ridge,” overlooking Ridges Basin, the site to be filled by the reservoir, he said.
One of the structures might be a tower because the posts are considerably overbuilt for the size of the structure, he said. Near the tower is a round structure with two rows of upright slabs surrounding it and no posts – a round, walled, open structure.
“It’s weird,” he said. “It might be a gathering area, a community center. We’re finding architecture up here that you don’t find in any other site. It’s really unique.”
This is the second season archaeologists have been in the field at Ridges Basin and nearby Blue Mesa, working in the warmer months and moving indoors to their labs in October. They have two more years to do field work and then three to complete reports and analyses.
The Ridges Basin area had been surveyed several times in the past, and some excavations had been done, but nothing on the scale of the effort now. While the goal is not to excavate everything, archaeologists want to recover crucial artifacts and obtain crucial data that will enable them to answer key questions about the early inhabitants of the area.
One of those questions is what sort of societies lived there and how they were organized.
“We’re finding that the architectural remains are a lot more variable then we anticipated,” Potter said, “leading us to think it’s not as cohesive a group that occupied the basin as had been thought.”
The remains of a large village sit in the middle of the basin, surrounded by loosely scattered houses. Potter said it’s unclear what the relationship was between the village and the small house clusters, or even whether they were all occupied at the same time
The Ancestral Puebloans lived in Ridges Basin a relatively short time, from approximately 750 to 850 A.D., during what archaeologists call the Basketmaker III to Pueblo I periods, Potter said. “We didn't know how dependent they were for food on domesticated plants such as corn, but we are finding evidence that they were heaviliy dependent,” he said.
They lived in pit houses, structures dug 6 feet into the earth and covered by roofs made from beams and brush.
Then they left, possibly moving to the southeast or northwest. The reasons for their leaving – whether environmental or because of social conflict – are another question to be answered.
They left behind a treasure trove of artifacts ranging from tools made of animal bones to redware pottery, unusual for this region of the Southwest, Potter said. Most of the ceramics have been grayware, but crews this fall found a whole redware jar on Sacred Ridge, buried in a pit. “We don’t know whether it was made locally or imported,” he said.
Potter’s favorite find was a well-preserved set of beads strung on a still-intact cord made from plant material. “I’ve never seen anything like that before,” he said. Numerous grinding tools, flaked stone tools, potsherds and projectile points have also been discovered.
The artifacts will be stored in the Anasazi Heritage Center near Dolores, which also holds the artifacts unearthed during the building of the Dolores Project, which created McPhee Reservoir. Human remains will be repatriated, along with any associated artifacts, at an undisclosed location in consultation with Native American tribes.
Dating the sites will be critical to analyzing the sequence and manner in which they were occupied. Gary Ethridge, crew chief for one of the several crews of six who did the excavating, said the roofs beams recovered should be able to be analyzed easily using tree-ring dating, or dendrochronology.
“We have some nice carbonized beams we can get dates from,” Ethridge said. “The dendrochronological time line is very important to archaeologists. We can see when the structure burned to the year.
“The Southwest is unique in that it’s such a dry climate that lends itself to preserving things and we have the type of forests and trees that lend themselves well to this type of dating,” he said. “We’re going to be able to date this very well.”
The study covers an area roughly 1.5 by 2 miles, Potter said, containing approximately 260 sites. By comparison, the Dolores Project involved about 1,000 sites. Nevertheless, the Ridges Basin excavations will provide archaeologists fodder for discussion for years to come.
“This is a really exciting project, very large,” Potter said.