Eons ago, a rushing lava river formed this pristine passage through solid rock.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

See massive fossils that are over 200 million years old in northeastern Arizona.

Dramatic river bend surrounds a natural red-rocked pedestal.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Most-visited and most-photographed slot canyon in the American Southwest.

Rippling sand dunes frozen in the Arizona rock.

This underground cave located in the most barren reaches of Idaho is filled with ice year-round.

These falls, sometimes called the "Niagara of the West," still put on a good show at the right time of year.

This set of hot springs also comes with fantastic views.

A creek tumbles over a series of step-like rocks to create this scenic water feature.

This pop-culture shop also offers the chance to become part of their favorite tv show or movie.

Rare and gorgeous birds abound in this protected wildlife sanctuary.

This landmark is a central figure in the Nez Perce origin story.

It was once used as a classroom to teach mining skills to local high school students.

Home to a timed geyser created by complete accident.

This trail leads to a mine that was used as a sanctuary during the Great Fire of 1910.

A wild west land agreement was etched right onto this historic Idaho stone.

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

A petroglyph map of the upper Snake River carved by prehistoric hunter-gatherers.

Despite his legacy of work in Spain, Cuba, and Florida, the larger-than-life writer's grave is a simple affair tucked in an Idaho cemetery.

A legal loophole makes it possible to get away with murder within this 50-square-mile section of Yellowstone.