Unlike canyons in other parts of the world, these weren’t slowly carved by rivers, but quickly excavated by massive floods during the most recent Ice Age.
In fact, the scale of the canyons at Potholes Coulee are so extreme that in 1910 they prompted geologist J Harlen Bretz to develop his theory of Ice Age floods.
Join Nick Zentner as he looks into the clues that Bretz found to come up with his groundbreaking idea.
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Nick on the Rocks: How were the Potholes Coulee canyons created?
North of Washington’s Gorge Amphitheatre are two massive lake-filled canyons, and geologists have chased clues about their origins for centuries.
Located just north of the famous Gorge Amphitheatre are two enormous lake-filled canyons that appear to feed into the Columbia River.
