
X-ray fluorescence technology has been used to identify the unique geochemical fingerprint of each separate deposit of obsidian, pinpointing the provenance of artifacts found elsewhere. MacDonald said.įor modern day researchers, the obsidian columns of Yellowstone have helped to reveal the travels and migration of people thousands of years ago. The cliff is “nationally significant because we had Native American groups from all over the country visiting it and collecting the stone and trading for it,” Dr. Over the last 11,500 years or so, the stone has been fashioned into deadly knives, razor-sharp spear points, darts for atlatls, or spear-throwers, and arrowheads. Obsidian is among the most prized tool stones in the world, and this particular deposit, nearly 100 feet thick, is exceptional because of its continual use by Indigenous people since the last ice age. MacDonald, a professor of anthropology at the University of Montana and the author of “Before Yellowstone: Native American Archaeology in the National Park.”

Known as Obsidian Cliff, the Yellowstone mountain is one of the country’s highest quality deposits of “the sharpest natural substance on Earth,” according to Douglas H. Spanning more than five square miles, the dark, sometimes translucent mass was formed from a rhyolitic lava flow that oozed out of the magma chamber of Yellowstone Caldera beneath the park, and cooled rapidly in the bitter cold of a glacial maximum, about 180,000 years ago.

Near the north entrance, an imposing mountain of black glass rises against the blue sky.
