Wild North America

The snowy crests of the Cascades conceal the most active volcanoes in the continental U.S. Foxes thrive on their slopes, tailed frogs mate in rocky streams and pine martens hunt in the alpine forests. But the mountains have a violent past and an uncertain future. These sleeping giants have the potential to erupt at any time, throwing the entire region into disarray.

Coastal California is home to one of the world's oldest and most iconic residents -- the redwoods. These old timers give shelter to an exuberant cast of animal characters. Thousands of convergent ladybugs use their roots to mate and hibernate while the wandering salamander can spend its entire life in the redwood canopy.

Life in Glacier Land is anything but easy. Especially when the delicate environment that so many critters call home dwindles away with the ever-heating sun. Global warming doesn't discriminate. All glacier wildlife is at risk, from the creatures that live around glaciers and especially those living in them.

From bears to beetles, life in the Colorado Rocky Mountain range is as resilient as its wildlife, regardless if they're big or small. Whether in sand, rock or river, wildlife is tested to see if they have what it takes to survive.

California's western edge teems with life above its shores and beneath the waves. Bus-sized humpback whales pause their migration north to snack on anchovy swarms. Elephant seals duel for control of the beach and the mating rights that follow. Meanwhile, tidal kingdoms emerge with the routine retreat of the sea.

Southern California is thought of as a haven for the rich and the famous. But just beyond the Hollywood Hills, life is anything but easy. Whether enduring the hottest temperatures in the country, or reaching for its tallest peaks, life here requires a great amount of knowledge, skill and just a bit of luck. See how humans and animals alike survive in Death Valley.