Spring has sprung and new life stirs on the Olympic Mountain ranges, the third great wilderness environment of this most diverse of national parks. The eponymous Olympic marmots awaken from their winter slumber to enjoy a feast, but must remain on the lookout for the bald eagle.

Sigrid concludes this "personal journey into the unknown" with optimism about harnessing creativity in order to live a more fulfilling life with Alzheimer's even though it might not slow it down. We have to live in the present!

In the summer, the denizens of Olympia National Park feed in the lush alpine meadows, while a mother bear and her cubs forage for food along the shore. Tasty and nutritious crabs make a perfect snack, even in their shells!

While the male bear is distracted by harbor seals, the cubs make their escape. Out at sea, the seals are safe from bears, but not from killer whales. Just to the north of the park lies a deep underwater canyon that can only be explored by submarine. It’s a birthing place for sharks, and a world of rarely glimpsed marine life.

In springtime, the sheer cliffs along the wild coastline of the park have become home to the common murre, a bird that comes to land only to breed. The eagles, further along in their nesting process, have a rapidly growing eaglet in need of constant nourishment, and, unfortunately, the murre colony makes easy pickings for them.

A fledgling bald eagle is the fastest-growing young bird in North America, yet it faces a challenging journey to maturity and acquiring its iconic adult plumage. As autumn storms arrive, king salmon migrate to river mouths and their freshwater spawning grounds, while resident orca pods expertly hunt them for a nutritious meal.

The king salmon swim upstream to spawn and complete their lifecycle, also providing a meal for a dipper. On the hillside, it’s the elks’ breeding season, and a black bear fattens up on berries before winter closes in across this magnificently diverse landscape.

There's been some bad news for the Great Barrier Reef, with experts declaring another mass bleaching—the fifth in just eight years. We find out what coral bleaching is and how it's impacting Australia's World Heritage-listed wonder.