Mysterious driftwood high in Grand Canyon caves hints at the legacy of Arizona’s huge impact crater.
SELIGMAN, AZ (AZFamily) — Twenty-one stories deep and about a mile off of old Route 66 sits the Grand Canyon Caverns. Formed over 15 million years ago, they were discovered in 1927, and tours began in ...
About 2,000 feet deeper than the Grand Canyon, Hells Canyon was rapidly carved when a lake spilled over about 2.1 million years ago, new research estimates. When you purchase through links on our site ...
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