Some of the most visited national parks in the country have a dark side. Aside from crowds of hikers, campers, and general tourists, there's a dark side to these three locations in California, the famous Yosemite, Joshua Tree, and Mount Shasta. From strange disappearances, grisly murders, and bone-chilling paranormal hauntings and ghost sightings, these pristine locales have a lot more to offer than just serene hiking trails or camping. In this second...

It's fall in the Sierra Mountains, and Anna Pigeon is slinging hash in Yosemite National Park's historic Ahwahnee Hotel. Four young people, all seasonal park employees, have disappeared, and two weeks of work by crack search-and-rescue teams have failed to turn up a single clue; investigators are unsure as to whether the four went AWOL for reasons of their own - or died in the park. Needing an out-of-park ranger to work undercover, Anna is detailed...

Coast through the dazzlingly diverse American West, winding around California's Big Sur on Route 1. Drive to the edge of the humbling Grand Canyon, steer through Olympic National Park, roll past the idyllic beaches on Hawaii's Kauai Island, and cruise through a blizzard of glorious landscapes and wildlife in Alaska.