Only known mainland rookery of the threatened Stellar sea lion.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

On the Oregon coast is a natural hole that seems to be draining the sea.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

This quirky hot springs town known to locals as "T or C" was named after a radio show.

A cave's rare beauty held a cavernous secret hidden underground.

In the remote high desert of New Mexico, a strange array of poles beckon fury from above.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A colorful, century-old cemetery of the Yaqui Indian Tribe hidden amid the suburban sprawl of Tempe, Arizona.

Petroglyphs, bird watching, and a 100-year-old Ranch in one location.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

One of the largest private collections of cars manufactured by the short-lived Franklin Automobile Company.

One of the most extensive and well-preserved collections of dinosaur footprints in North America.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

These free-roaming horses were once destined to disappear from the land.

An artificial crater field that trained astronauts for lunar exploration.

Don't blink or you'll miss it.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

Thousands of Mexican Free-Tailed Bats soar around an abandoned storm drain at sunset each summer.

A spiritual vortex among the red rocks in Sedona.