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

A short but powerful waterfall resides amid Colorado’s Great Sand Dunes.

Up-close opportunities to see working birds of prey.

Above Breckenridge, a destructive mining technique sits sunken in a small pond.

Located in the world's highest-altitude Dark Sky Community, this observatory welcomes amateur and professional astronomers alike.

This remote Colorado canyon is home to the second-largest collection of natural arches in the world.

It takes a nine-mile hike to reach these hot springs, but weary hikers are rewarded with stunning views and a warm soak.

Isak Heartstone, a 15-foot wooden troll made out of recycled materials.

The site of a defunct mill, that once supplied marble for the construction of the Lincoln Memorial.

Birds with backpacks expedite film development for a rafting company on a remote Colorado river.

This nearly abandoned town was once a thriving mining community until a series of fires.

Two creeks flow out of either end of this canyon in opposite directions.

A river runs through this remote valley in a very unexpected way.

Unlike most arches, this geological oddity formed in a volcanic dike.

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

Small teepee-like houses built for TB patients have become sheds, studios, and bus stops around Colorado Springs.

This interpretive path lets you get up close and personal with dinosaur bones.

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

The largest source of fossilized insects anywhere.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.