A historic cavern 210 feet below ground along historic Route 66 in northwestern Arizona has finally reopened for tours. Grand Canyon Caverns, in Peach Springs near the Hualapai Indian Reservation, ...

While Arizona is famous for its stunning landscapes and dramatic rock formations, some of the best things to see here are underground. Arizona has numerous famous caves — some readily open to the ...

Corrections & Clarifications: An earlier version of this article gave an incorrect location for Grand Canyon Caverns. A historic cavern 210 feet below ground along historic Route 66 in northwestern ...

The Grand Canyon’s valleys and millions of years of rock layers spanning Earth’s history have earned it a designation as one of the Seven Natural Wonders of the World. But, according to a new UNLV ...

For years, scientists were mystified by the origins of Hells Canyon, the deepest river gorge in North America. This massive natural wonder is a staggering ten miles wide and plunging more than 2,400 ...

The Grand Canyon’s valleys and millions of years of rock layers spanning Earth’s history have earned it a designation as one of the Seven Natural Wonders of the World. But, according to a new UNLV and ...

A team explores relationship between warming post-Ice Age temperatures and intensifying summer monsoon rains on groundwater reserves. The Grand Canyon's valleys and millions of years of rock layers ...