Spanning an elevation of 160 feet and containing 388 steps, this is Seattle's longest staircase.

The decorations were inspired by an unlikely missing treasure.

This playground sculpture of an icon from the past is dedicated to the children of the future.

The only bridge in the United States where BASE jumping is legal without a permit year-round.

Multiple monuments to a grizzled old mutt that survived the landscape of Butte's treacherous Berkeley Pit.

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

A beautiful geyser under environmental threat.

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

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.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

"Polynesia on the Plains."

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

One of the largest private collections of fossils in the world.

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.

This towering wooden Sasquatch was carved with a chainsaw.

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

The first declared National Monument in the United States.

The rockpile was the founding landmark for the town of Gillette, and is now the home of the region's history.

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

Before its closure in 2002, this South Dakota mine was the largest and deepest gold mine in Western Hemisphere.

A cemetery housing wild west legends in South Dakota.

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