NASA launches ‘space archaeology’ project in Greater Chaco area

The Great Kiva and Casa Rinconada are prominent features of Chaco Culture National Historical Park in northwestern New Mexico. Ancestral Puebloan culture flourished in the San Juan Basin from the 800s to the 1100s. The approximately 30,000-acre park preserves a fraction of ruins in the region. This summer, a NASA team, using thermal imagining technology, documented ruins that lie outside the park’s boundaries and face threats from potential oil and gas development.

John Kantner spent the better part of his career as an archaeologist trying to unlock the mysteries of the ancient Chaco Canyon civilization. He, like many of his colleagues, was left with only theories and shots in the dark.

Courtesy of NASA

NASA conducted thermal imaging in the Greater Chaco area this summer. The thermal map on the left confirms the location of ruins from a survey conducted in the 1980s. Thermal imagining detects different ground temperatures and can reveal buried sites.

The problem seemed to be that the answer to lingering questions about the flourishing society’s ways lied outside the canyon’s walls, sprawled out over hundreds of miles around the high desert, which remain largely undocumented.

But this past summer, NASA, in partnership with several other organizations, launched in the Greater Chaco area “space archaeology” campaign, an increasingly popular method of research that uses aerial and satellite thermal imagery to find buried historic ruins.

The hope, according to project managers, is to catalogue previously unknown structures, roads and other sacred relics beyond the Chaco Culture National Historical Park boundary in northwestern New Mexico, before it’s too late.

“There’s no doubt that a lot of the oil and gas development has destroyed remnants of the ancient Chacoan people,” Kantner said. “If we can use remote sensing to detect below surface, we might be able to answer some of these questions before further degradation.”

Searching outside the parkThe Chaco Culture National Historical Park is comprised of about 30,000 acres of windswept landscape between Farmington and Albuquerque, regarded as the cultural center of the ancestral Puebloan people from about 900 to 1150 A.D.

Within the remote and isolated canyon, carved over thousands of years by the Chaco wash, are the architectural remains of an ancient urban complex of great houses, kivas and other structures that have withstood the region’s harsh climate for centuries. Today, the site is regarded as the most dense and concentrated collection of pueblos in the American Southwest.

But what lies outside the park’s gate is what concerns Kantner and other archaeologists, as well as the tribes that hold these places to be sacred. The park, protected from oil and gas development, is only a link in a larger society known as the Greater Chaco area, which extends hundreds of miles around the 4,600-square-mile San Juan Basin.

Yet, as the oil and gas industry inches closer to the park, ready to drill the mineral-rich Mancos Shale, it’s been challenging to identify the exact location of ancient roads and structures.

Most ruins have been swallowed by the earth in an already extremely inaccessible landscape, and the need to catalogue those sites before any further degradation occurred became a top priority for land managers, said Tom Lincoln, assistant cultural resources director for the National Park Service.

“The number of oil and gas wells that could be drilled in that area is in the thousands,” Lincoln said. “And when you’re doing an extractive exploration for oil and gas or other minerals, it can have significant effect on environment, in this case historic ruins.”

That’s where NASA stepped in.

Survey finds sites at riskIn the mid-1980s, NASA began flights equipped with thermal radar detection over the Greater Chaco region, looking for changes in surface temperature, which would indicate whether structures, completely or partially buried, were present.

“Every object has a temperature,” said NASA’s Jeffery Luvall. “And that temperature is different than the soil underneath. So when you see the map, the different colors stand out.”

Those early explorations found miles of 30-foot-wide roads cut across the high desert, some pointed true north, interpreted by many as a ritualistic feat, the purpose of which is unknown even today.

Advances in understanding the ancient society, which at its height was home to thousands of ancestral Puebloan people, were spearheaded by many local, state and federal agencies over the years. But NASA, for the most part, directed its attention elsewhere.

In the 1990s, the mineral-rich San Juan Basin became the target for high-intensity oil and gas drilling. Over just a few decades, more than 20,000 wells and their supporting infrastructure populated the basin.

Just last month, as a result of the encroaching infrastructure, the park – which holds a UNESCO World Heritage and Dark Sky Park designation – earned a spot on top of the Western Value Project’s list of sites at risk from oil and gas impacts.

Building digital mapsThe immediacy local land managers felt to document the myriad sites around Chaco caught the attention of NASA’s DEVELOP program, said Carrie Heitman, an assistant professor of anthropology at the University of Nebraska-Lincoln.

Over the course of six weeks this summer, researchers guided graduate students in beginning to build a digital map that aims to plot all known cultural resources in the Greater Chaco area, which Heitman hopes the Bureau of Land Management will take into account when planning for future energy development.

“It’s a highly fraught landscape right now, with multiple lawsuits,” Heitman said. “And it’s bound to get more complicated.”

The survey, using NASA satellites and sensory equipment, found 44 of 123 known great houses at risk for disturbance by industry actions, Heitman said, but only 19 are federally protected. Dozens of roads and other sites, previously undocumented, were recorded.

The new technology is the next evolution of thermal imaging that was used in the 1980s, Luvall said. And though the equipment provided higher resolution and reasonable success, there’s still more work to be done.

“You don’t rely totally on imagery,” Luvall said. “You have to go out on the ground, too, and that involves a lot of effort in digging, time and financial expense.”

Over the next couple of years, the project managers want to expand the study area, and when possible, conduct ground explorations.

“Hopefully, we’ll be able to connect these hundreds of Chacoan standing structures and road segments with each other. From an archaeological perspective, it’s very exciting,” Lincoln said.

But with 90 percent of the San Juan Basin’s land managed by the BLM already leased to oil and gas drilling, the last 10 percent has become a battleground between interests of resource development and cultural preservation.

What’s left is significantRecently, the BLM delayed, for the third time, the sale of more than 2,000 acres for oil and gas development, which would allow fracking on land that nearly 25 tribes hold sacred. However, the BLM has said the parcels could go up for auction as early as January.

“This is, if you will, their landscape,” Lincoln said of tribal descendants of the ancestral Puebloans. “It has a dramatic effect on what happens to their tribal and religious history.”

Efforts to reach representatives with various tribes for this story were unsuccessful.

Paul Reed of the advocacy group Archaeology Southwest is part of a grass-roots coalition pushing the BLM to engage in a Master Leasing Plan, which would more intensely plot future drilling. He also hopes the agency will implement at least a 10-mile buffer around the park.

“We’d love to go back in time and manage the landscape differently, but at the same time, what is left in that 9 percent is significant,” Reed said. “And we need to put our full effort in protecting those areas.”

Wally Drangmeister, spokesman for the New Mexico Oil & Gas Association, said the industry is aware of the cultural sensitivity in the area, but given the massive expanse of the basin, and the fact some leases date back as far as the 1930s, he asked, “Where do you draw the line?”

“The Greater Chaco region could be a fourth of New Mexico,” Drangmeister said. “We absolutely understand the concept (of a cultural landscape) but it does have its limits. Some people don’t want to see power lines or any other impacts of man, but we think that’s not the intent of the law nor practical.”

The BLM, for its part, wrote in an email that it conducted its own Light Detection and Ranging (LiDAR) survey recently, the data of which should be available by the end of the year.

“Part of the BLM’s mission is multi-use and sustained yield,” spokesman Zach Stone wrote. “This is accomplished with a balance between preservation and development. We do not develop in any wilderness area or area of historical cultural sites if at all possible.”

Requests for comment to the Navajo Nation and state of New Mexico, entities that also own land in the basin, were not returned.

A great society’s footprintsKantner now works as the associate vice president for research and is dean of the graduate school at the University of Northern Florida in Jacksonville, a world away from the arid West.

But, still, he lights up with curiosity when talking about what Chaco meant to the indigenous people. A pilgrimage destination? A centralized authority? A trading post? Why is there evidence of goods, such as turquoise and pottery, coming in, but never going out?

The ancient dwellers abandoned Chaco when a 75-year drought hit, eventually dispersing into present day Hopi, Zuni and Acoma tribes, among others. But the footprints of a great society, along with the questions, for now remain.

“Chaco seemed to always be the ceremonial center,” he said. “And a big part of that was the visual connection, you could see almost all the important points, like Mount Taylor, on the horizon.

“If that aspect gets compromised, people won’t be able to get a sense of what Chaco Canyon meant to these indigenous tribes, if all they see are pumps going up and down all day long, looking like Texas.”