Over the past few decades, in Tennessee, archaeologists have unearthed an elaborate cave­art tradition thousands of years old. The pictures are found in dark­ zone sites-places where the Native American people who made the artwork did so at personal risk, crawling meters or, in some cases, miles underground with cane torches-as opposed to sites in the ‘twilight zone,’ speleologists’ jargon for the stretch, just beyond the entry chamber, which is exposed to diffuse sunlight. A pair of local hobby cavers, friends who worked for the U.S. Forest Service, found the first of these sites in 1979. They’d been exploring an old root cellar and wriggled up into a higher passage. The walls were covered in a thin layer of clay sediment left there during long­ ago floods and maintained by the cave’s unchanging temperature and humidity. The stuff was still soft. It looked at first as though someone had finger­painted all over, maybe a child-the men debated even saying anything. But the older of them was a student of local history. He knew some of those images from looking at drawings of pots and shell ornaments that emerged from the fields around there: bird men, a dancing warrior figure, a […]