A fearsome American badger is on the hunt, and the prairie dogs are not even safe in their burrows. The north rim of the canyon thunders with rutting bison, as the big males lock horns to establish superiority.

Sigrid describes the first part of her trip from Long Island to New Jersey, taking a moment to tell us about the famous Verrazzano Narrows Bridge.

With the winter drawing in, the animals prepare once more for that harshest of seasons within the breathtaking confines of the world’s greatest gorge, the Grand Canyon National Park.

Forged by the volcanic heat that still bubbles at the heart of this great American wilderness, the mighty Yellowstone was the first of America’s National Parks. Located mostly in Wyoming, it is a place where bison roam free and the gray wolf has returned, re-establishing the natural order of the ecosystem.

Food is scarce during the harsh winter months, and the battle to survive is intense. The successful wolf pack hunts constantly to feed each hungry mouth, and the weary bison must dig through layers of snow if they are to feed at all.

Sigrid seeks to answer the question "What's a borough?" In doing so, she talks about how New York City got its start, and also about the surrounding counties that played an important role in its development. In this video, you'll see 18th- and 19th-century maps of the area.

Creatures large and small, from the bison to the ephydrid fly, make use of hot springs to survive the coldest winter months. Others, like the bears, hibernate, emerging ravenous when the weather finally warms, and ready to scrap for whatever food they can find.

Warm sunshine melts the last of the winter snow, and in the valleys of Yellowstone, animal mothers give birth to their young, bringing them into a beautiful yet perilous world.

The Bronx was the first area to become part of New York City. Lying to the north and northeast of Manhattan, it was a logical addition. The quirky name of this borough has its own history.

Yellowstone is home to a small cougar population, but theyare rare and seldom seen. The noisy ruffed grouse or “thunder chicken” is far less elusive, as the males “drum” their wings loudly in the breeding season, advertising their presence to any nearby female birds.

As soon as it can stand, a young bison calf follows its mother and the herd, even through rivers of ice cold melt water. Meanwhile, the carcass of a bison that did not survive is fought over by wolves and grizzly bears.

The borough of the Bronx has gotten a bad name because of issues with poverty and crime. It's also had its share of neglect and mishandling on the part of local and state administrations. However, the Bronx also has some claims to fame, such as the Bronx zoo and botanical garden.

A young bison calf is swept away by the icy torrent as the herd crosses a river. Against the odds, it washes up on a small island, but with night approaching, and its mother nowhere in sight, the outlook seems bleak for this little one.

In the first of two parts, we look at Brooklyn's beginnings and how it came to be one of New York City's boroughs.

Without its pack, a wolf is a far lesser threat, and the other animals know it. However, for the lost bison calf, trapped on a small island, a lone wolf is a mortal danger, one that would take a minor miracle to survive.