Original subtitles

Earth, 18,000 years before the present

it's a world locked in cold

at the height of the last great Ice Age.

Across tens of thousands of years

unmelting snows have compacted into massive glaciers.

Buried under ice sheets averaging a mile thick

are lands where hundreds of millions live today.

As Earth's water is increasing locked up in ice

sea levels plummet more than a hundred meters.

Exposed sea floor nearly joins Australia to Southeast Asia

Japan becomes part of mainland Asia.

Across North America, ice fields and glaciers

envelop all of Canada and northernmost United States.

As the Ice Age spreads, Alaska emerges as a crossroads.

Off it's Bering sea coastline

the retreating ocean exposes a great land bridge

a thousand miles wide connecting Asia to America.

Across this corridor, a river of living creatures would flow.

It was the genesis of a great wave of life

that would inhabit the Americas, and this was it's Eden.

Crossing into ancient Alaska

migrating herds find new forage and sheltering valleys

but they're followed from Asia by fierce carnivore...

saber-toothed cats, giant bears

and the greatest of all predators.

They arrive in small bands from Siberia

pressing east in pursuit of game

unaware they're discovering a continent.

The hunters are sustained by bison, moose, woolly mammoth

and the wild reindeer called caribou.

Where frozen tundra limits vegetation, meat is life.

Most of the year, it is kill or starve.

The hunters prosper here across millennia

but as the receding Ice Age

opens the wall of glaciers to the south

most move on with the herds

into the virgin continents beyond.

Their descendants will become Apache and Sioux, Aztec and Maya

Inca and Amazonian.

Yet some remain in Alaska.

For them, this is a world of mysterious forces and spirits.

To science, the Aurora Borealis is created

by streams of charged particles from the sun

colliding with the atmosphere.

To some Native Americans, the Northern Lights

were children not yet born at play in the heavens.

Here at the far edges of existence

the wildness of the ancient earth

never vanished.

Even today, the solitude of the past

is broken only occasionally by the sound of the present.

In Alaska, the last great Ice Age survives.

Vast regions appear as lifeless as a frozen planet.

Sheer walls a mile deep loom as monuments to the power

of the glaciers which carved them.

Most of its rugged terrain can be crossed only with wings.

Massive snowfalls compress glacial ice

so dense in some places

only a single color of the spectrum is reflected...

an ethereal blue...

chilling and strangely beautiful.

Where the frozen rivers end

icebergs are born in a spectacle so mighty

native tribes call it "While Thunder"

Some blocks are the size of 30-story buildings.

It would seem a place too hostile for living things

but each year, after a winter that can last nine months

Alaska erupts with life.

Hundreds of thousands of birds

stream here from as far away as Antarctica

to breed in Alaska's protected cliffs and coves

and to feed on it's rich seas.

For one brief season of abundance

life flourishes.

Ice-falls turn to waterfalls.

Grasses emerge, fueled by up to 24 hours of sunlight a day.

Animals hurry to store up nutrients

before winter returns.

Without the plenty of the warm season

life couldn't survive the long months of bitter cold.

Famished from half a year of hibernation

even the lordly brown bear

is content to graze in spring

sharing the meadows with caribou too fleet to be caught.

As bellies fill, play begins.

There is other business conducted

in the fields of fresh grass...

the age-old rite of spring.

They will remain a couple for only a day or two

sharing a rough affection.

Bear hugs will lead to the conception of new life

to be born in the hibernation den

in the dead of winter.

A world of extremes

Alaska is swept by enormous tidal fluctuations.

Low tide can drain an entire bay like a bathtub.

Taking advantage of the low tides

brown bears roam the exposed tidal flats.

To dig for clams.

Any protein is welcome in the effort

to replenish a body that can weigh 1,400 pounds.

Perhaps noticing the success

of mother and cub, an imitator arrives.

But clamming is not as easy as it looks.

For a red fox, survival is, in part, knowing when to give up

and just move on.

As summer's warmth deepens

Alaska's three million lakes turn to gathering places.

Beavers prepare

for the ravages of cold weather ahead

by repairing their lodges.

Moose feast on tender aquatic plants

hidden on lake bottoms.

Wolf pups gorge on mother's milk

to reach near-adult size before winter arrives.

But the serenity of summer

can be shattered by the approach of an intruder.

The black bear has a fearsome reputation

but it's the most playful of bear species

and with the coast clear and the water cool

even a bear may succumb

to the impulse merely to have fun.

Life along the coast, too, is eased by the warm season.

After a winter battered by North Pacific storms

sea lion colonies haul out to sun themselves

like vacationers enjoying a day at the beach.

A game of King of the Mountain ensues.

In the world of sea lions, size matters...

but patience succeeds.

Ungainly on shore, the sea lion moves in the sea

with the ease of a circus performer...

both acrobat and clown.

Like its meadows, Alaska's seas bloom with fertility

under the lengthening daylight.

So rich are the waters

humpback whales swim nearly 4,000 miles from Hawaii

to revel in Alaska's season of abundance.

Humpbacks fast for eight months

in the relatively sparse waters of the tropics

where they breed and give birth.

For survival, they depend almost entirely upon the krill

and small fish that concentrate here in summer.

To capture the immense quantities

of food they need

some humpbacks have devised an extraordinary technique

of cooperative feeding.

Diving in unison

they surround a school of herring

while one or more sings a ritual feeding song.

Simultaneously, a whale blows a circular net of bubbles

around the fish.

Then, as the trap is completed

the entire group rockets upward through the bubble bath.

Each species finds a way to survive.

Humpbacks have learned to invent

and, more importantly, to cooperate.

In summer, a miracle arrives from the sea

in wave after wave

salmon return from the open ocean

and embark on a final migration inland

to spawn in the same streams of their birth.

Silver bodies transfiguring for the act of spawning...

a phenomenal sense of smell guiding them...

they sweep into Alaska by the millions

in a vast flood of life.

They face a marathon journey upstream

sometimes hundreds of miles long

yet they persist

even in the face of impossible obstacles.

For brown bears, the arrival of salmon

is the most important feeding event of the year.

It's the last opportunity to add the bulk they need

for the months of winter hibernation ahead.

Dominant bears claim the best fishing spots.

Such confrontations are rarely bloody.

Size is power.

The subordinate merely finds another spot.

Bears are not born with fishing skills.

Each develops a highly specialized

style of fishing.

There's the scanner

and the apprentice scanner.

The pouncer.

The submariner.

Easily distracted.

The snatcher.

For the submariner

the key is not to be graceful but persistent.

Most bear fish singly and selfishly.

Only a mother shares her catch.

For some, greed prompts its own style of fishing...

the mugger.

The salmon banquet is brief.

Nothing is wasted.

Many feed, but with hibernation time approaching

none more urgently than bear.

To store up fat, bears may fish 20 hours a day.

Large males can put on 300 pounds.

Success in the world of the brown bear

is a simple matter of reaching one's sleeping weight.

Some reach it a little too soon.

For salmon that make it past the gauntlet of predators

time is running out.

Powerful instincts have brought them back

to lay and fertilize the eggs of the next generation.

Only one of a hundred born here have survived to perform

this final act

and in giving life, all will die.

Their eggs will develop beneath the ice of winter

in water enriched

by their parents' decaying bodies

turning loss to renewal, ending to beginning.

After as few as six weeks of warmth

the air grows chilly.

Summer visitors head south to escape the fierce cold ahead.

The first snowfall can arrive in August.

Now Alaska's animals must employ every instinct and adaptation

for winter survival.

As many as 4,000 eagles gather along the Chilkat River

in the southeast

the largest known congregation of bald eagles in the world.

Though most Alaskan rivers freeze

geothermal heat keeps the Chilkat open

enabling the eagles to feed

on the river's unusually late salmon run.

Somehow, bald eagles know to return late each fall

to the one place that will help ensure their survival.

One Alaskan animal actually yearns for the onset of winter.

Where most creatures would perish from exposure

polar bears thrive.

Their body heat is preserved by thick fat

and an insulating fur of translucent, hollow hairs.

The summer breakup of offshore ice

has marooned them on land

where they can't hunt their favorite prey

the ringed seal.

For now, they survive only on stored fat

and buried seaweed and wait patiently

for the sea to freeze over so the hunt can resume.

Some males while away the time in friendly play-fighting.

For a female and her youngster the long wait is a time

of both motherly affection and danger for the cubs.

Despite the fierce protection of mothers

fewer than half survive their first year.

Accidents and starvation are persistent threats

but she must also avoid her own kind.

Male polar bears will eat unprotected cubs.

Few mothers in all of nature are as devoted as a polar bear.

Cubs learn early to obey her commands.

Finally, the sea freezes over.

The season of waiting and fasting ends.

With their extraordinary sense of smell

they can detect a seal 20 miles away.

The feast of winter is about to begin.

Elsewhere in Alaska

a time of darkness and scarcity arrives.

Caribou migrating to wintering grounds

scrape beneath the snow day or night

for moss and sedge grass.

Searching for food

they're vulnerable to hungry predators.

For a family of wolves

prey are easier to track in snow.

With jaws powerful enough

to crush the caribou's largest bones

they will leave little behind.

For a species that must cooperate

to survive, rivalries are brief

the leader's dominance nearly absolute.

As the full fury of winter envelops Alaska

temperatures can reach 50 below zero or lower.

Elk have learn to change their diet in winter

to feed on only the highest protein forage available.

Yet it is a harsh time for yearlings.

Half will not make it.

Bison, protected by shaggy hair over head and shoulders

also grow a special winter fur

to cover their hindquarters.

The musk ox is outfitted with broad hooves

to walk on snow

and a winter undercoat of cashmere-like wool

softer than a lamb's and impervious to the cold.

Alaska's last horned survivor

of the Pleistocene Age

it embodies the resiliency and adaptability of life

in it's battle with the elements.

Humans, too, have adapted to the land of winter.

Called "Eskimos" by outsiders

descended from peoples who crossed the ice age land bridge

the Inupiat learned to use every resource in their frozen desert.

For food, they turned to the sea.

Still today, they watch for arriving bowhead whales.

If the Inupiat have been respectful

they believe a whale will give itself to them as a gift.

The hunt, sanctioned by international law

is a sacred ritual to the Inupiats.

Hauling in it's body

they thank the whale

for the gift of life-sustaining nourishment

to combat the piercing cold.

For other humans, the cold has posed a mortal threat

recorded dramatically in images of another age.

In 1897, one of history's largest gold strikes

drew a quarter-million "stampeders"

through the snowbound passes of Alaska

towards the gold fields of the Klondike.

Anticipating easy wealth

they trudged headlong into an Ice Age.

Half the prospectors would never even reach the gold fields.

Arriving ships were marooned eight months by ice.

Many attempted to make the journey with pack horses.

The animals died by the thousands.

Hundreds of men died from exposure

or were buried alive in avalanches.

Of the quarter million who came, perhaps 400 struck it rich.

Yet some who failed to find easy wealth were inspired

by the challenges of this new land.

Like waves of others across the ages

they adapted to Alaska and stayed on.

Five, four, three, two, one... go.

Before a crowed that includes descendants

of those "stampeders"

dog sled teams set out from Anchorage each year

to commemorate the Gold Rush

in a thousand-mile race known worldwide as the Iditarod.

In the defiant spirit of Alaska

winter's harsh challenges are turned to rugged sport.

Each year, as the warm season approaches

the vast spectacle of life's resiliency

unfolds again in Alaska.

The days lengthen, grasses reemerge

and along stream bottoms

the promise of the future is renewed.

Mere glimmers of life now

salmon hatchlings will soon depart

to return years hence and nourish Alaska

as a miracle of summer that sustains life in winter.

It's a land of countless streams

and mountain peaks still unnamed

a place shaped by ice and solitude.

In Alaska, we are witnesses to the triumph of life itself.

Here, we can rediscover a vitality

vanishing from our lives

and reawaken the spirit of the wild

remembered not in our minds, but in the blood and the heart.

Whether or not we will ever reach Alaska

we all want to know that such a place still exists.