Robert Redford narrates as professional kayakers Rush Sturges and Evan Garcia take on the boiling rapids and brutal falls along the Columbia River Gorge. Eddy Cartaya and Barb Williams venture deep into the dangerous and mysterious ice caves of Mt. Hood. Finally, Bill Anders and Jennifer Gifford clear access to the bizarre and natural phenomenon that is Crater Lake - celebrated as being "Like No Place Else On Earth."
Hang-glider pilots launch themselves over Yosemite Valley during a wildfire, a marine biologist takes a memorable dive through a Channel Island kelp forest and an arborist scales to the very top of a towering redwood.
Wildlife filmmakers capture incredible footage of a grizzly and wolves competing for food in Yellowstone National Park, climber Conrad Anker does a late winter ice climb in Hyalite Canyon and a summer rock climb on Devils Tower.
Adventurers are first to descend the treacherous white waters on Hudson River Gorge, athletes climb the Shawangunk Mountains' cliffs, a 17-year-old glider pilot flies over Adirondack Park, and devoted staff restore Central Park.
Highliners walk 400 feet above the floor of Mineral Canyon, a 73-year-old rancher fights to preserve her historic cattle ranch and descendants of an ancient civilization restore the ruins of an irreplaceable American artifact.
A marine researcher works to solve the mystery behind the bioluminescence of Vieques's Mosquito Bay, a cave explorer battles a dangerous underground river, and locals snorkel in the hidden, colorful paradise of Hurricane Hole.
Extreme cave divers venture deep into the dark abyss of Jackson Blue cave, a maritime archaeologist dives to a historic Civil War shipwreck, and a burn boss uses raging wildfires to preserve Corkscrew Swamp Sanctuary.
Mountain bikers ride down steep rock faces in Sedona, photographer Ian Ruhter captures visuals with a camera built from a truck, and equine aficionado Becky Standridge protects one of the nation's last known herds of wild horses.