Obsidian Cliffs

Obsidian was quarried at Obsidian Cliffs, now in Yellowstone National Park, as long as 11,000 years ago and, thanks to trade among the continent’s early peoples, has turned up at ancient sites across North America from western Canada to the Ohio Valley.

Visitors to the park will find the cliffs on the Great Loop Road between Mammoth and Norris. For more information, visit the National Park Service web page linked above.