Decades since the possibility was first suggested by researchers, a growing body of evidence suggests cannibalism was practiced among the regions ancestral Puebloans.
Some of the most convincing evidence to support the theory was uncovered in Durangos backyard Ridges Basin, located next to Bodo Industrial Park.
Archaeological excavations conducted in 2005, before water began pumping into Lake Nighthorse, yielded thousands of bone fragments with the characteristic markings of traits linked to cannibalism.
The findings were only recently publicized, in a scientific paper that appears in the current issue of the Journal of Anthropological Archaeology.
The number of bone fragments 15,000 is more than has been documented at any other previously studied ancestral Puebloan site. They date to around 800 A.D., the Pueblo I period.
Despite the large number, they are believed to have come from only about 35 people.
There was evidence of breaking and cutting off flesh, cooking and pulverizing, said archaeologist Jim Potter, principal investigator with SWCA Environmental Consultants, who led the excavations.
The topic of cannibalism among the ancestral Puebloans popularly known as the Anasazi has been discussed widely among archaeologists since at least 1969, when a then-young archaeologist from Arizona State University, Christie Turner II, presented findings and a paper in Santa Fe at an archaeological conference.
The excavations conducted at Ridges Basin were required by federal law, which says a record must be created when archaeologically significant land is disturbed by federal projects.
Potter discussed the evidence of cannibalism reluctantly and gingerly aware of modern sensitivities.
Today, the popular image of the ancestral Puebloans is of peaceful farmers who built architectural wonders still widely admired by hundreds of thousands of visitors annually at Mesa Verde National Park, Chaco Canyon National Historical Park and other ruins throughout the Four Corners.
But the reality is more complex.
The descendants of the ancestral Puebloans are the modern-day Pueblo Indians of New Mexico, the Hopi and the Zuni. Potter acknowledged the evidence of cannibalism was tough for them to take.
Its just such a taboo for them, he said.
Potter said work done at Ridges Basin was organized and supported by the Ute Mountain Ute Tribe, who are not descendants of ancestral Puebloans.
Terry Knight, the historical preservation officer for the Ute Mountain Utes, declined to be interviewed for this story.
The Utes encouraged Potter to report his scientific findings, but they asked that he delay talking to newspapers until a more complete understanding of the site came into focus.
Part of the reluctance to talk about the findings at Sacred Ridge, a little knoll on the west end of Ridges Basin, came from the experience in the 1990s at Cowboy Wash, near Dolores.
Coprolite, fossilized human fecal matter, was discovered at the site that tested positive for human DNA making the discovery one of the more convincing findings pointing toward cannibalism.
Scott Ortman, director of research at Crow Canyon Archaeological Center, said communication about the Cowboy Wash discovery lacked sensitivity.
In the 90s, the language was fairly sensational to get people to pay attention to this, Ortman said. Maybe thats what was needed to get the field to look at this more closely, but it was done in a way that was not very respectful to the American Indians at that time.
When Potters team discovered the evidence of cannibalism in 2005, Potter said they were chastened by the Cowboy Wash experience, and they wanted to be more careful.
Now that the facts are known, Potter says the main task is understanding their meaning.
We know these sites are out there, and these events occurred. Now we need to know why and when these events occurred. Weve got the forensics down, he said.
Potters paper about the excavation at Sacred Ridge points to social and political breakdowns of the ancestral Puebloan culture as precursors.
Potter rejects climate change leading to scarce resources as the cause because at the same time, about 800 A.D., migration into the area was occurring near Dolores.
Analysis of the bone fragments showed the victims were related, from a nearby village.
I think it was ethnic conflict, Potter said. They were neighbors. Its what you see now in Rwanda. Why do people treat neighbors this way? If you can create an ideology of the others, it can be a powerful thing.
Potter added: It was not an idyllic period where you hunt and kill a bunny, then sit around a campfire and sing Kumbaya.