The Obsidian Cliffs. Stone from these cliffs is found as far east as the Hopewell Mounds in Chillicothe, Ohio, dating to 400 A.D. indicating extensive pre-historic native American trade routes across North America.

Image ID: amer0174, NOAA's Small World Collection
Location: Wyoming, Yellowstone National Park
Photo Date: 2011 June 28
Photographer: Dr. David Goodrich, NOAA (ret.)


• High Resolution Photo Available