Nature has shaped this drainage tunnel into the digestive tract of a mighty beast.

When it was built in 1929, this historic bridge was the only place to cross the Colorado River for 600 miles.

A sharp bend in a dramatic river canyon cut through red rocks.

The fifth-longest natural arch in the world, and the longest outside China.

Contains a wealth of information about the first exploration and later use of the Green and Colorado Rivers.

A spectacular overlook of the Little Grand Canyon of the San Rafael River, a deep sandstone gorge streaked with orange, red and white in a remote, uncrowded part of Utah.

Idaho’s largest, deepest limestone cave is known for its quirky rock formations and bat population.

A Rocky Mountain city provides a happy ending for a pinto pony and his Brobdingnagian red chair.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

This sidewalk tribute honors Colorado's great culinary creation.

This prehistoric karst cave is situated near a working ranch and historic warm springs.

Once a menacing challenge for trailblazers, this trail is now the most scenic drive in Utah.

Stripes of flowers bloom each spring in a 50 acre rainbow of color.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

Artist Jack Pierson made this surreal sculpture in honor of Wonder Valley, a countercultural community on edge of civilization.

A pair of large white marble lions guard this stretch of the Mojave Desert, and it is utterly mysterious how they got there.

The self-proclaimed gateway to the Extraterrestrial Highway.

Narrow slot canyons in a badland eroded into soft sedimentary rock provide an otherworldly landscape in this remote Nevada state park.

A land of debatable treasure.

Odd outsider art installations surround a Gold Rush-era ghost town.

The most magnificent bottle house in a town strangely full of them.

Twelve plaster figures inspired by da Vinci's famed painting haunt the desert landscape above a real-life ghost town.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.