An important piece of history from mankind's journey to the moon sits in the lobby of a government science lab.

This remote desert watering hole has a connection to a curious chapter of American history.

This oasis-like spring in the Sonoran Desert is home to unique, endangered species.

These elusive, isolated rodents evolved into a distinct, locally iconic subspecies.

A mass grave for victims of an airline disaster that led to much-needed safety improvements for commercial flights.

A stone pillar commemorates the surrender of the extraordinary Apache leader.

The remnants of an early automobile route across shifting sand dunes can still be found in the deserts of Southern California.

The eroded core of an ancient volcano is now accessible by a short hike.

This huge dam across the Colorado River caused an armed standoff between two U.S. states.

This Old West prison built into the side of a cliff was said to be inescapable.

This fireplace-turned-monument pays tribute to the assassinated U.S. president.

The remote resting place of a notorious Wild West outlaw whose death is shrouded in mystery.

This old-fashioned candy shop, ice cream parlor, and diner served as the setting for one of TV's most controversial series finales.

The stone circle honors the 19 firemen who perished during the Yarnell Hill Fire.

A suburban museum tells the story of a historic transportation network and even provides rides in antique trolley cars.

This ancient trail has claimed the lives of over 2,000 people.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.

The notorious Wild West outlaw was raised in this unassuming abode.

A Maryland museum dedicated to Black history, housed in a historic church.

An innovative attempt to break a siege in the American Civil War still scars the earth today.

The ruins of Theodore Roosevelt's beloved ranch stand in a forgotten corner of a national park named after him.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

A partial tunnel blasted into a steep ridge is all that remains of a failed railway across Arizona.

Arizona's first government hub is a rustic cabin now preserved as part of a historical museum.