Rock Art Discovered in Deep Dark Caves Reveal Early Human Civilization on Puerto Rico's Uninhabited Mona Island. Published Oct 30, 2017 at 11:01 AM EDT Updated Oct 30, 2017 at 12:07 PM EDT.

The Mississippian Period (A.D. 1000-1500) is the last precontact phase in the Southeast before Europeans arrived, and this was when much of the dark-zone cave art was produced.

The first dark-zone art in the Southeast was discovered in 1979, when two local cavers shimmied down a cave passage in Tennessee and noticed an image of a bird incised into a mud wall.

Since cave art was first documented in North America in 1979, Dr. Simek and Mr. Cressler have been studying what is known as dark-zone cave art, which involves exploring passageways unreachable by ...

The Mississippian Period (A.D. 1000-1500) is the last precontact phase in the Southeast before Europeans arrived, and this was when much of the dark-zone cave art was produced. Subject matter is ...