A38A2256-430B-4C8D-BCD3-0BF6404517D4 Published 2021-09 at 2048 × 2048 in A38A2256-430B-4C8D-BCD3-0BF6404517D4 Big Obsidian Flow is the youngest lava flow in Oregon Big Obsidian Flow is the youngest lava flow in Oregon