The largest earthwork effigy in the world.

This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

The site of the "Bone Wars" between two rival paleontologists during the dinosaur rush of the 19th century.

Toss a Frisbee through the ruins of this Colorado gold mining town.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

Rather than a run-of-the-mill franchise hotel, this lodging has been decked out in dinosaur decor.

The highest bridge in America was built for an almost unnervingly small amount of money.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

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

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

A black cottonwood gets a second life as a home for books.

Sweet Willy, at 30 feet tall, is the world's biggest beagle.

This museum glorifies the humble potato.

A small Wyoming town is home to the state's oldest-operating soda fountain.

One of the largest collections of wildlife art in the United States, built into the side of a cliff in rural Wyoming.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

Native Americans built this circle of stones, which was used to predict astronomical events.

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

The last physical evidence of the Lewis and Clark trail is one of their autographs etched into this giant rock.

Concrete strongholds stand guard over the Golden Gate.

The southernmost outpost of the Russian Empire in colonial America.

The longest burning light bulb in the world.

One of the world's largest collections of rare and magnificent bird specimens.