Obsidian Cliff

Pine trees on top of a dark cliff at the edge of a meadow
Obsidian Cliff, designated a National Historic Landmark in 1996, is located on the Grand Loop Road between Mammoth and Norris.

NPS

 

Significance

  • Obsidian is found in volcanic areas where the magma is rich in silica and lava has cooled without forming crystals, creating a black glass that can be honed to an exceptionally thin edge.
  • Unlike most obsidian, which occurs as small rocks strewn amid other formations, Obsidian Cliff has an exposed vertical thickness of about 98 feet (30 m).
  • Obsidian was first quarried from this cliff for toolmaking more than 11,000 years ago.
  • It is the United States’ most widely dispersed source of obsidian by hunter-gatherers. It is found along trade routes from western Canada to Ohio.
  • It is the United States’ most widely dispersed source of obsidian by hunter-gatherers.
  • Obsidian Cliff is the primary source of obsidian in a large concentration of Midwestern sites, including about 90% of obsidian found in Hopewell mortuary sites in the Ohio River Valley (about 1,850–1,750 years ago).

Recent History

About 90% of the forest on Obsidian Cliff plateau burned in 1988. The fire did not damage the cliff face, but it cleared the surface, creating optimal conditions for archeological surveys. Those surveys added substantially to knowledge about how obsidian was mined from the bedrock and collected as cobbles from the overlying glacial till. Staff are now researching the intensity of use of this obsidian, both within the park and across North America.

The kiosk at Obsidian Cliff, constructed in 1931, was the first wayside exhibit in a US national park. It was listed on the National Register in 1982. The site was designated a National Historic Landmark in 1996.

 
Brown and gray columns of rock make up a cliff that towers up to a deep blue sky.

The Earliest Humans in Yellowstone

Human occupation of this area seems to follow environmental changes of the last 15,000 years.

Dead branches leaned up against a tree in a conical shape form a wickiup.

Historic Tribes

Many tribes have a traditional connection to this region and its resources.

Three uniformed people working around excavated dirt. Two stand by wooden boxes; one uses a shovel.

Archeology

Archeological resources are the primary and often only source about humans in Yellowstone.

An historic postcard of a large tent camp and stage coaches

Places

Every place and building in Yellowstone has a story.

Stones piled in a formation in the forest

Park History

Learn about Yellowstone's story from the earliest humans to today.

Last updated: September 16, 2019

Contact the Park

Mailing Address:

PO Box 168
Yellowstone National Park, WY 82190-0168

Phone:

307-344-7381

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