The Obsidian Cliffs. Stone from these cliffs is found as far east as theHopewell Mounds in Chillicothe, Ohio, dating to 400 A.D. indicating extensivepre-historic native American trade routes across North America.
10/22/2018 11:58:44 AM
Photographer: Dr. David Goodrich
Affiliation: NOAA (ret.)
Date: 2011 June 28
Location: Wyoming, Yellowstone National Park