

The largest cave drawings in North America have been discovered in Alabama, according to a study by Jan F. Simek, Stephen Alvarez, and Alan Cressler in the archaeology journal Antiquities.
The five large figures discovered include three anthropomorphs (humanlike figures), one swirling, enigmatic figure, and a snake, most likely an eastern diamondback rattlesnake that was sacred to southeast Indigenous people of the time. The smallest figure measures about 3 feet and the largest, the snake, stretches about 10 feet in length, marking the largest known cave drawings in North America. The drawings were not made with pigment but rather incised into the walls.
It is unknown what the figures represented to the Native Americans who made them in the Middle Woodland period some 2,000 years ago.
“They are not recognisable characters from ethnographically recorded Southeast Native American stories, nor from archaeologically known iconographic materials,” the article says. “They do, however, share certain themes with other known regional rock art, such as anthropomorphs wearing regalia, rattlesnakes and symbolic emergence from rock. Thus, they probably depict characters from previously unknown religious narratives.”
Additionally, the researchers explain that Native Americans of the American Southeast saw caves as entrances to the underworld, and thus the figures probably represent spirits that typically reside in that divine space, which differ from the spirits of the upper world.

The discovery was made possible by the use of 3D photogrammetry, a technique in which many photos of a space are taken and then used to model a 3D rendering of a space.
The cave in which the drawings were made has very low ceilings, meaning that to view even the smaller drawings ones, which were discovered in 1998, one has to be lying down. But once the ceiling was mapped out, these large figures invisible to the naked eye appeared.
“They are so large that the makers had to create the images without being able to see them in their entirety,” the scholars wrote. “Thus, the makers worked from their imaginations, rather than from an unimpeded visual perspective.”
This accidental discovery marks the first time photogrammetry has been used to find unseen drawings, but the scholars predict this technology may find new glyphs in American caves.