While the Grand Canyon is Flagstaff's easy-access claim to fame, this even quicker jaunt from the Arizona city offers ...

Building monstrous mounds of mulch — known as mulch volcanoes — around the base of a young tree creates several immediate problems.

For decades, scientists knew magma was simmering beneath the earth at Yellowstone National Park. A team of researchers ...

A river that drained the slopes of a now-vanished volcano may have carved Yosemite Valley's depths during the last 10 million years.

Moonrise and Earth’s shadow looking east from the crater’s rim. The red-and-black volcanic cinder cone, located in Arizona’s Painted Desert, last erupted around 900 years ago. Michelle ...

Chilean police recently rescued a 78-year-old German tourist who became stranded in his car near the Olca volcano, close to the Bolivian border, according to local news reports and authorities.