North America's deepest gorge, Hells Canyon, which slithers along the border of Idaho and Oregon, is a surprisingly new ...

Hells Canyon is the deepest river canyon in the United States. Now scientists have solved the mystery of when it formed.

Hells Canyon, which is on the border between Oregon and Idaho, is almost 8,000 feet deep ... cave is about 1,200 feet above the modern-day Snake River. Eventually, by exploring over 30 caves ...

Everything’s bigger in the US, they say, and that apparently includes its river gorges. But don't be fooled by its grand size ...