Strange geologic landmarks in the Pacific Northwest are the lingering remains of a mystery that took nearly half a century to solve. These features turned out to be a result one of the most powerful and bizarre episodes in geologic history.
This region experienced dozens of major, devastating floods over the course of more than 7,000 years.
Thanks to Franz Anthony and Studio 252mya for the flood and lake illustrations. You can find more of Franz's work here: https://252mya.com/gallery/franz-anthony
Produced in collaboration with PBS Digital Studios:
http://youtube.com/pbsdigitalstudios