An architect's childhood fantasy treehouse made real.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

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

The first declared National Monument in the United States.

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

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

Over thousands of years, this slot canyon was carved out of the bed of an ancient lake.

A town honors its legacy of traditional American Indian pipe carving with one gigantic pipe.

A striking sculpture built to honor the women of the Lakota and Dakota Nations.

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

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.

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

A cemetery housing wild west legends in South Dakota.

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

A fitting attraction for the corn capital of the world.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

Eight feet in diameter and more than 24 feet around.

This massive roadside mascot was the first version of the giant to illustrate his butt.