The early Native Americans in the upper regions of the United States fashioned their tools and weapons from a type of rock called obsidian. This type of igneous or volcanic rock is glassy, oily, and black that produces fine and sharp edges that were perfect for prehistoric stone tools. These rocks can be found at the eponymous geographical landmark, the Obsidian Cliff.

The Obsidian Cliff is located in northwestern part of the Yellowstone National Park in Wyoming. This cliff was a volcanic rock formation formed millions of years ago. It is regarded as a kind of prehistoric quarry where early settlers dug the rocks for their spear points, knives, or arrowheads used primarily for hunting and preparing food.

An Obsidian Cliff Kiosk is located in the park where visitors can look around and buy souvenir from the park.