Titans clash along California's big coast where rugged highlands meet the deep ocean.

The Land of Giants, where the tallest trees in the world tower over the Californian coast.

The High Cascades conceal the most active volcanoes in the Lower 48 that could erupt any time.

The perilous peaks of western Montana hide an ancient secret, America's glacier lands.

The amazing life around the Rockies, from low valley meadows to the peaks of its mountains.