Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

Population: 1.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

Hidden behind Lincoln's head is a chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

A place where the laws of nature seem to have gone completely berserk... but of course haven't.

Every president in history is immortalized in bronze in downtown Rapid City.

South Dakota's oldest operating brewery is housed inside a historic firehouse.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

Thanks to a loophole in property ownership, this alleyway has become a cacophonous street gallery.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

A cemetery housing wild west legends in South Dakota.

Seth Bullock, the sheriff of Deadwood, built this town immediately after Teddy Roosevelt’s death in 1919.

This vintage train once gave new meaning to “swimming upstream.”

Yes, this monument is aware that it is about 20 miles away from the actual center of the United States.

The crumbling structure is a rare surviving relic of the area's bygone mining industry.

This shallow pit was once used to send over 20,000 buffalo plummeting to their death.

An antique Beechcraft airplane serves as a giant windsock for people driving through the blustery open country of eastern Wyoming.

The first declared National Monument in the United States.

One man's ambition created this psychedelic log home.

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