Yesterday Barb and visited the Big Obsidian Flow in central Oregon. As is the case with many volcanic fields it is somewhat other worldly. It’s a flow composed of about 25% obsidian mixed with pumice. It is an easy hike and very worthwhile.
There are huge chunks of the black natural glass all around you:
You need to be careful when stepping on it because it is very slick. You are told not to bring your dog with you on the trails because, well, broken “glass” is everywhere.
The native Americans who lived nearby used the obsidian for tools and traded it with other tribes.
Because the chemical makeup of the flow is distinguishable from other sources scientists were able to trace tools found hundreds of miles away to this flow.