A whole mountain of volcanic glass in the Oregon high desert, and one of the best obsidian collecting sites in the world. It is not just black: there is rainbow sheen, gold and silver sheen, mahogany, snowflake and the prized fire obsidian, all free to collect on this BLM ground for personal use. Knappers come from everywhere for it. PUBLIC (BLM), between Bend and Burns; high, remote and dry, so come prepared and take a real spare.
Obsidian (rainbow, mahogany, fire)
See it on the map
Other places on the map within a couple of hours.