YELLOWSTONE NATIONAL PARK, Wyo. — Near the north entrance, an imposing mountain of black glass rises against the blue sky. #ifttt #nyt #science

Obsidian Cliff: Humanity’s Tool Shed for the Last 11,500 Years YELLOWSTONE NATIONAL PARK, Wyo. — Near the north entrance, an imposing mountain of black glass rises against the blue sky. Tags: ifttt, nyt, science via Pocket https://ift.tt/QD4iFZN March 22, 2023 at 12:30AM

Obsidian Cliff: Humanity’s Tool Shed for the Last 11,500 Years YELLOWSTONE NATIONAL PARK, Wyo. — Near the north entrance, an imposing mountain of black glass rises against the blue sky. Tags: 500 years, obsidian cliff: humanity’ via Pocket https://ift.tt/QD4iFZN March 22, 2023 at 01:13AM