Podcast | The epic forces that shaped the Columbia River
Ice, fire and colossal floods: Knute Berger digs into the river’s tumultuous geologic history with lessons from Nick on the Rocks’ Nick Zentner.

Knute Berger and Nick Zentner walk near the Columbia River in Eastern Washington. (Alley Rutzel for Cascade PBS)
The Columbia River has been carved up by more than a dozen dams over the past century. But it’s the colossal floods and lava flows from millions of years ago that truly set it on its winding path.
How do we really know what we know about the Columbia?
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To better understand this history, Cascade PBS’s resident historian Knute Berger joined forces with geologist Nick Zentner of Nick on the Rocks in a recent episode of the Mossback’s Northwest video series. But there’s much more left to unearth.
In this episode of Mossback, Berger joins co-host Stephen Hegg to discuss his decision to spend half of this past season of Mossback’s Northwest on different aspects of the Columbia River. They also dig into the massive floods and lava flows that made the Columbia River what it is today; what it was like for Berger to work with Zentner on this project and other geological inquiries over the years; and the enthusiastic response from viewers, including one observation of a mistake in the video that led Berger down an entirely new path.