Scientists trace the story of human presence in the Red Desert back 12,000 years. Striking evidence of early human inhabitants is seen in rock art found at the Boars Tusk, East Flaming Gorge, and Seedskadee areas. Researchers interpret the petroglyphs carved into rock at these sites as biographical, ceremonial, or spiritual expressions. The Red Desert's Black Art petrogylph is thought to date back 11,500 years, according to anthropologist and cultural historian Russell L. Tanner who says the rock art may be the continent's oldest.