Archaeologists have made a huge discovery deep inside a damp cave in northern Alabama. At a subterranean ceiling just half a meter high, researchers have uncovered the largest cave art discovered in North America: intricate etchings of human-like figures and a snake carved by Native Americans more than 1,000 years ago.
“This is exemplary and important work,” says Carla Klehm, an archaeologist at the University of Arkansas, Fayetteville (UAF).
Although the American Southwest is famous for its petroglyphs carved into canyons and cliff faces, much of the Southeast’s rock art is hidden underground in caves. “Forty years ago, nobody would have guessed that there was a lot of cave art in the Southeast,” says Thomas Pluckhahn, an archaeologist at the University of South Florida who was not affiliated with the paper. But in recent decades archaeologists, including Jan Simek of the University of Tennessee, Knoxville, have shown that is not the case.
Simek first visited the 19th unnamed cave – so named in scientific papers to protect its exact location on private land – in the 1990s. In its cool, humid depths, where no external light penetrates, Simek and his colleagues’ flashlights revealed faint impressions on the ceiling depicting birds, snakes, wasps, and overlapping line patterns. The art resembled designs found on Southeastern pottery from the Woodland period between 1000 B.C. and 1000 AD were found
The cave’s ceiling drops to just over half a meter where the glyphs are, so researchers had to lie on their backs to see most of the images, Simek explains. There’s nowhere to stand and see the entire ceiling, he says.
To get a more complete picture of the art, Simek revisited the cave in 2017 with Stephen Alvarez, a photographer and founder of the nonprofit Ancient Art Archive, which documents ancient rock art around the world and shares it online via virtual reality. Alvarez wanted to use a new technique called 3D photogrammetry to create a realistic 3D model of the cave — and see if they could uncover additional images that had gone unobserved in a confined space.
The researchers climbed down into the cave and used a tripod to start taking pictures. Over a period of 2 months, they captured almost 16,000 overlapping, high-resolution images. Next, they stitched the photos together using computer software to align the images in 3D space; Researchers could then manipulate the resulting model using virtual reality software, Alvarez explains. “We could light the room any way we wanted and leave out the floor” to practically step back and see the entire ceiling, he says.
When the researchers manipulated their images to make the drawings easier to see, five giant glyphs emerged that were previously too large and faint to see. These included three humanoid creatures in royal robes, a whirling figure with a rattlesnake’s tail, and a long, scaled snake. The images are between 0.93 meters and 3.37 meters long, making the largest of them the largest piece of cave art in North America, the researchers report today in antiquity.
The images, which were probably created by etching in fresh mud on the damp ceiling, are undated. Fragments of charcoal and streaks of wood smoke on the cave walls, perhaps from the artists’ torches, date from the first millennium. The Woodland Indians who lived in the area at this time lived in village settlements, built large mounds for religious worship, and traded extensively in the South, East, and Midwest. Their descendants stayed in the region for centuries; but by the late 19th century, many were being forced west as part of the fledgling US administration’s policy of expelling Native Americans.
The newly described figures share features with other rock formations to the Southeast, such as cliff carvings at Alabama’s Painted Bluff, and also to the Southwest, such as the human-like pictographs at Canyonlands National Park. The figures also resemble those found on Woodland style pottery. Though the exact meaning of the glyphs is unclear, caves like the one in which they were found were often associated with the underworld, the researchers say.
In completing the work, the authors consulted with the Eastern group of Cherokee Indians, whose tribal homeland includes the area where the cave is located.
Creating the glyphs required “an extraordinary level of artistry,” says UAF George Sabo. But much about the artists remains a mystery. “Who were they in their churches?” he wonders.
Although the cave’s location is not disclosed to protect the art from vandals, the team created a video of their model for everyone to explore virtually. Klehm is excited that 3D photogrammetry continues to unveil hidden art elsewhere — and make it accessible. “[This] can help us see things we can’t see, to go beyond what the human eye is used to looking for,” she says.