A rare wayfinding portmanteau of “Street” and “Avenue.”

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

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

This Moab institution functions as both a rock store and a small natural history museum.

Despite its name, this route in southern Utah offers a heavenly day trip.

A tunnel with windows, so you don't miss out on the impressive views.

This isolated outpost was once the only place to cross the Colorado River for hundreds of miles.

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

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

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

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

Home to a timed geyser created by complete accident.

A cemetery housing wild west legends in South Dakota.

The first declared National Monument in the United States.

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

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

An architect's childhood fantasy treehouse made real.

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

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."

For thousands of years, Native American hunters drove buffalo straight off this cliff in Montana's Yellowstone Country.

This small museum is home to some of the oldest and best-preserved dinosaur specimens found in Montana.

This amazingly preserved Gold Rush town is a historian's dream.