Hells Canyon, the deepest river gorge in the United States, was carved just about 2.1 million years ago — making it much younger than the Grand Canyon. Matthew Morriss hide caption ...

Grand Canyon Caverns is about 123 miles from Grand Canyon National Park's South Rim, according to Google Maps. Details: 115 Route 66, Peach Springs. 928-422-3223, gccaverns.com .

Hells Canyon, the deepest river gorge in the United States, was carved just about 2.1 million years ago — making it much younger than the Grand Canyon. Matthew Morriss ...

It's cut through by the Snake River and is North America's deepest river gorge, at 10 miles (16 kilometers) wide and about 1.5 miles (2.4 km) deep — almost 2,000 feet deeper than the Grand Canyon.

Hells Canyon might be deeper than the Grand Canyon, but it's barely 2 million years old, ... In the very first cave the group explored (about 1,200 feet above the modern river), ...

More information: Matthew C. Morriss et al, Cave records reveal recent origin of North America's deepest canyon, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas ...

A century-old mystery claims that Egyptian-style artifacts and dozens of mummies were discovered in an underground complex within Arizona’s Grand Canyon. Led by G.E. Kincaid and financed by the ...