Asteroid Impact May Have Triggered Mega-Flood in Grand Canyon

New research suggests the Barringer Crater's formation 56,000 years ago could have caused landslides that dammed the Colorado River.

Apr. 11, 2026 at 8:43pm

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A highly textured abstract painting in earthy tones of ochre, sienna, and turquoise, featuring sweeping geometric arcs, concentric circles, and precise botanical spirals, conceptually representing the interconnected geological forces that shaped the Grand Canyon landscape.An ancient asteroid impact may have triggered a massive flood that reshaped the Grand Canyon, according to new geological evidence.Flagstaff Today

Recent geological research indicates that the impact that formed the Barringer Meteorite Crater in northern Arizona around 56,000 years ago may have also triggered a series of events leading to the creation of a massive, previously unknown lake within the Grand Canyon. Driftwood and other evidence found in caves high above the Colorado River suggest a landslide caused by the crater's formation temporarily dammed the river, flooding a large section of the canyon.

Why it matters

This discovery not only deepens our understanding of the Grand Canyon's geological history, but also highlights the interconnectedness of natural phenomena. It shows how a single cataclysmic event like an asteroid impact can have far-reaching consequences, altering the landscape in ways that remained hidden for millennia.

The details

Researchers led by geologist Dr. Karl Karlstrom of the University of New Mexico found driftwood samples in Stanton's Cave, located over 40 meters above the Colorado River, that dated back around 35,000 years. This suggested a massive flood had occurred, much larger than any known in the region's recent history. Further analysis of additional driftwood samples found the material was actually around 56,000 years old, coinciding with the estimated age of the Barringer Crater's formation. The researchers theorize the crater's impact produced ground shaking equivalent to a magnitude 3.3-3.5 earthquake, which could have dislodged limestone boulders in Nankoweap Canyon and temporarily dammed the river, creating an 80-kilometer-long lake reaching up to 90 meters deep.

  • The Barringer Meteorite Crater formed around 56,000 years ago.
  • Driftwood samples found in Stanton's Cave date back around 35,000 years.
  • Additional driftwood samples collected in 2023 date back around 56,000 years.

The players

Dr. Karl Karlstrom

A retired geologist from the University of New Mexico who grew up in Flagstaff, Arizona and has studied the geology of the Grand Canyon region.

Karlstrom's father

Also a geologist who explored the caves of the Grand Canyon and discovered driftwood in Stanton's Cave in 1970, leading to the initial theory of a massive ancient flood.

Chris Baisan

A dendrochronologist at the University of Arizona who assisted in the research.

John Spray

A planetary scientist at the University of New Brunswick who commented on the research, though not directly involved.

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What they’re saying

“It would have required a flood ten times bigger than any known flood over the last 2,000 years.”

— Dr. Karl Karlstrom, Geologist

“There was an area where it looked like the canyon wall had collapsed across the river.”

— Chris Baisan, Dendrochronologist

“They're certainly close, if not contemporaneous.”

— John Spray, Planetary Scientist

What’s next

The researchers continue to collect additional samples from caves in the Grand Canyon National Park, uncovering more evidence of ancient lake deposits and suggesting multiple generations of lakes in the area over thousands of years.

The takeaway

This research not only deepens our understanding of the Grand Canyon's geological history, but also highlights the interconnectedness of natural phenomena. It shows how a single cataclysmic event like an asteroid impact can have far-reaching consequences, altering the landscape in ways that remained hidden for millennia.