The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

At the time of its completion, it was the tallest dam in the world.

This town is home to the world’s largest arch constructed entirely of elk antlers.

Around half a million years ago, these magnificent columnar basalt cliffs were formed from cooling lava.

This rustic old building is said to be the most photographed barn in America.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

One man's ambition created this psychedelic log home.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

An architect's childhood fantasy treehouse made real.

A beautiful geyser under environmental threat.

One of the last socialist halls still standing in the United States.

Modeled after a famous church in Vienna, Austria—but in Helena, Montana.

A sprawling museum located on the former site of the Orphan Girl Mine.

An entire town preserved as a historic landmark.

High in the Rockies the third largest statue in the U.S. opens her welcoming arms, and lights up the night sky.

A 6-mile-long lake created by an apocalyptic seismic event and the deadly chain reaction that ensued.

The residents at this Yellowstone wildlife park will certify your cooler as "bear-proof."

New fungal and bacterial species call this deadly lake home.

The only bridge in the United States where BASE jumping is legal without a permit year-round.

Supposedly Satanic numbers adorn this preserved submarine sail.

Jail from the 19th century that was built by inmates.

Home to the deepest rift anywhere on Earth.