Natalie Behring for The New York Times Obsidian ... New York Times Yellowstone was established on March 1, 1872, when President Ulysses S. Grant signed the Yellowstone National Park Protection ...

Editor’s Note: This story accompanies the May 2016 issue of National Geographic magazine, devoted entirely to America’s first national park ... in Yellowstone. In samples gathered at Obsidian ...

Black Sand Basin is located near Old Faithful making it an easy stop along the Grand Loop Road in Yellowstone National Park. Distance ... Look for black obsidian around the edges of the pool.