Nature Notes | Archeologists Win a “Race Against Time” in Documenting the Ancient Murals of the Pecos Canyonlands

Dr. Carolyn Boyd, founder of the Shumla Center, at the White Shaman Shelter on the Pecos River. The mural here – some 2,000 years old – is one of more than 300 found in the Lower Pecos Canyonlands.
Dr. Carolyn Boyd, founder of the Shumla Center, at the White Shaman Shelter on the Pecos River. The mural here – some 2,000 years old – is one of more than 300 found in the Lower Pecos Canyonlands.

Archeologists Win a “Race Against Time” in Documenting the Ancient Murals of the Pecos Canyonlands

By Andrew Stuart

At the threshold of West Texas, where the waters of the Pecos and Devils rivers mingle with those of the Rio Grande, and the Chihuahuan Desert blends with the Hill Country and the South Texas plains, there exists a singular legacy of the deep past: hundreds of murals painted on caves and canyon walls.

In their beauty, and their scale – one spans more than 300 feet – these “Pecos River Style” murals have long captivated archeologists and artists. Yet recent research has added insight to appreciation. Archeologist Carolyn Boyd has shown that the compositions can be deciphered. There are ideas and stories here that resonate with traditions elsewhere in the Southwest and Mexico, and that locate the human experience in the great cycles of the heavens and the seasons.

It’s a testament to the expansive worldview of the people who hunted, fished and gathered plants in this land thousands of years ago. And today it’s imperiled.

Founded by Boyd, the Shumla Archaeological Research & Education Center is working to document it while they can. They’ve had tremendous success, overcome obstacles, and earned for this borderlands treasure some of the recognition it deserves.

Jessica Lee Hamlin is Shumla’s executive director.

“It was such an incredibly ambitious project,” Hamlin said. “I don’t really think we fully understood what we were getting into when we did it, which probably is a good thing.”

In her award-winning book, The White Shaman Mural, Boyd showed that the site, rather than a collection of disparate images, was a single, planned composition. And she found in its vivid renderings of human figures, animals and abstract forms a creation story. She and her colleagues began to see this “painted landscape” as a library – with each mural a book. Shumla named its preservation effort the Alexandria Project.

When the ancient library at Alexandria, Egypt burned, much of classical knowledge was lost. Likewise, this rock art is vanishing.

The Lower Pecos region is a labyrinth of limestone canyons – and rockshelters, or shallow caves, in these canyons were canvases for ancient people. There are 350 murals in Texas – most in Val Verde County. An unknown number exist in Mexico. The mural tradition began more than 4,000 years ago – and continued for 3,000 years.

In 1969, the Rio Grande here was dammed, to create the Amistad Reservoir. Many rock art sites were inundated. In the intervening years, the reservoir has backed up into tributary canyons – murals originally placed high above canyon floors are now at water’s edge. And though it remains an arid place, the reservoir has increased humidity – which in turn has intensified spalling: the limestone “canvases,” and the art they contain, are breaking apart.

Shumla was founded in 1998, and the organization has well-developed techniques for documenting rock art. But the Alexandria Project was launched in 2016 with a sense of urgency.

“In 2016, we thought, How are we going to reach these sites fast enough?” Hamlin said. “It was that really heavy weight on our hearts that – that we’re doing incredible work, and the work we’re doing is preserving these sites, but we’re not doing it fast enough, and we’ve got to find a way – in a scientifically correct manner – to get to them faster.”

Their mission was to document the murals in such a way that, even when they are lost, researchers can continue to unlock their secrets.

Some of the murals are on public land – Seminole Canyon State Park manages some of the most spectacular, including Panther Cave – with its 10-foot-long, red-painted mountain lion. And Shumla, which is based in the tiny town of Comstock, has longstanding relationships with many local landowners. But there was also an element of exploration – finding new sites, and tracking down sites that hadn’t been studied in decades. Shumla developed new relationships with landowners – many of whom, Hamlin said, quickly became proud stewards of the ancient art on their property.

At each mural, the team mapped the coordinates. They recorded the context – details like the size and orientation of the rockshelter on which the mural was painted. Then they used a “GigaPan” system to obtain high-resolution, two-dimensional images.

“The 2-D is important,” Hamlin said, “because it can be so high resolution that you can zoom in and zoom in and zoom in, as a researcher, wherever you’re looking at it, and really see brushstrokes, and even deeper, to the grain-of-sand level. It’s really incredibly high-resolution.”

With these murals, however, 2-D isn’t enough. The works are “site-specific” in the deepest sense – the creators incorporated the undulations of cave walls, the divots and cracks, into their compositions. To capture that relief, the archeologists use another painstaking technique, called “structure from motion photogrammetry.”

At small murals, this “level 1” documentation could be completed in a matter of hours. But at large murals, the process could take days. In the coming years, Shumla plans to return to select sites for “level 2” and “level 3” documentation. That could involve digital microscopy, which would reveal the order in which paints were applied, and radiocarbon dating.

By the end of 2019, the Shumla team – seven archeologists, and a changing cast of interns – had documented 163 sites. Their goal was to reach 225 in 2020, which meant they’d have to accelerate their efforts even more.

Then the pandemic hit. It brought fieldwork to a halt. But with new safety protocols, the team got back out and resumed its work.

“We kept everyone safe,” Hamlin said, “and we were able to get to 70 sites in 2020, despite two months out of the field, despite working from home – I can’t speak highly enough about the team being able to do that.”

The project has generated unexpected challenges – including how to maintain, catalogue and safeguard the immense amounts of digital data the archeologists have collected.

Shumla is a nonprofit, dependent on donations. To curate the material, they’ve partnered with the Center for Archeological Studies at Texas State University. For now, researchers must come to Shumla’s headquarters in Comstock. But Texas State will soon have a work station at its San Marcos campus. Ultimately, an online platform could allow researchers, and members of the public, to explore the 3-D models and high-resolution imagery.

Shumla has also helped raise the profile of the canyonlands murals. In collaboration with Texas Parks & Wildlife, Shumla applied with the National Park Service – and in 2021, the Lower Pecos Canyonlands Archeological District was recognized as a national historic landmark.

There’s more documentation to be done – and the most exciting work – of probing the mysteries and meaning of the rock art – lies ahead. These monumental works can be seen today – at Seminole Canyon State Park, or on tours of the White Shaman Shelter, offered by the Witte Museum. Encountering the sweeping scenes of wildlife and of human figures with upraised arms is powerful. Thankfully, these ancient works have devoted advocates.

Nature Notes is supported by the Shield-Ayres Foundation and produced by Marfa Public Radio with the Sibley Nature Center. The program can be heard each Tuesday and Thursday, at 7:45 a.m. and 4:45 p.m., Central time, on KRTS Marfa, 93.5 FM, and KXWT Odessa/Midland, 91.3 FM. This episode was written by Andrew Stuart.