Geology in the United States

This large chunk of dark rock is a relic from an ancient volcanic eruption.

On the edge of this small Washington Park, a piece of the Earth's mantle has come to the surface.

A set of tall pillars and alcove-like rooms that are significant to the Miami people of Indiana.

In 1912, this idyllic Alaska landscape was blown apart in the largest volcanic eruption of the 20th century.

Despite the name, it's unclear if this small depression in northern Nye County was actually caused by falling space debris.

Colorful outcrops and cliffs just north of Reno provide a scenic backdrop for hiking and mountain biking.

Harder layers in colorful sandstone weather out as prominent “fins" and even more intricate and bizarre shapes.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

These pink granite water slides are the result of millions of years of erosion.

The strongest earthquake in Nevada's recorded history left these spectacular breaks along the west front of a range in central Nevada.

The oldest pictographs on this decorated rock formation in California's Carrizo Plain date back as many as 4,000 years.

The “Grand Canyon of Maine” is a three-mile gorge full of striking geological features.

Generations of rockhounds got their start at this beloved, historic mine.

Once an ancient sea, this landscape of rocky ravines is filled with the fossils of ancient marine life.

More than 350 million years ago, western New York was covered in a vast sea. Today, you can dig up the remains of the plants and animals that lived there.

On the edge of grassland in northeastern Colorado, these rock formations are some of the few remnants of a high plain that has eroded away over millions of years.