National Park Mysteries, Cleveland National Forest

A series of incidents in Big Bend National Park leave experts convinced of secret alien activities taking place there.

Discover the forces living in the secret underworld of Death Valley National Park, where a series of deaths and disappearances have taken place.

Explore Cleveland National Forest, where reports of gun-wielding ghosts, savage creatures and otherworldly portals are rife.

A trip through the ginormous forest in Arizona. Strange encounters rumoured to have happened there include an alien abduction.

A stroll through a national park that is the alleged underground base for a powerful secret society.

Some claim that the dark, mysterious energies that surround this national park point to treasures from a lost civilisation that are hidden there.

Built by the ancient Anasazi, spooky sightings in this national park include shape-shifting creatures and time-traveling Wingmakers.

The infamous Yosemite National Park has a darker side that includes mysterious sightings, disappearances and even a prehistoric pterodactyl.

A stroll through Great Sand Dunes National Park, where strange lights, animal mutilations and other bizarre incidents have been spotted.

Reports of sightings here include reptiles - known as reptoids - who work with aliens and can appear in human form.

This tourist hotspot is also rumoured to be the epicentre of dark and sinister forces from Native American lore that lure visitors to their deaths.

A demonic truck driver, disembodied voices, nightmarish skinwalkers and a time loop are all reported to exist in Canyonlands National Park.