Jeff Corwin begins his journey on America's highest mountain, Mount McKinley, and then travels through the 6 million acres of Denali National Park in his search for the ultimate prize, Denali's grizzly bears.

Explore the untold beauty and diverse marine life of the Kenai Peninsula. Jeff negotiates ice-choked bays, battles with monster halibut and encounters breaching whales.

Journey through Katmai National Park & Preserve, a 4-million acre wilderness and home to the largest population of brown bears in the world, as well as one of the biggest salmon runs on earth.

Travel to the most westerly points in the U.S., a remote island called Attu. Jeff gets close to humpback whales, arctic foxes and enormous bears.

Join Jeff as he travels to southeast Alaska in search of the world's largest gathering of American bald eagles. Along the way, he does some extreme fishing, encounters 60-foot totem poles and goes cross-country skiing and snowmobiling.

As fall turns to winter, Jeff travels to the interior of Alaska where temperatures hover around zero. Jeff spends a night outdoors, gets a bird's eye view of the winter scenery and challenges an Iditarod Trail Sled Dog Race winner to crazy dog vs. snowmobile race.

Jeff continues his journey through the stunning scenery of Alaska, focusing this week on the animals that have survived near-extinction, including the American buffalo, the fur seal, the timber wolf and the killer whale.