Mountain: Life at the Extreme

High above the clouds...

..there are lost worlds.

Unexplored...

..unforgiving...

..wildly unpredictable.

But on the great mountain ranges of our planet, life does exist.

Against all odds,

a few extraordinary animals

and remarkable people

make their home in the highest places on Earth.

WIND WHISTLES

In the Rocky Mountains,

you can sit all day and watch the world go by...

..without seeing a soul.

Slap bang in the middle of busy North America...

..for as far as the eye can see,

it's just wilderness.

In the Rockies, the weather can change on a dime.

It can shift from scorching

to Arctic in a few hours.

To make it here,

it's vital to know

when to act

and when to wait.

In the Rockies, it's all about picking that perfect...

..moment.

The Rockies are the spine of North America.

They rise up in the South West,

travel north through Colorado, Wyoming,

Idaho, Montana, and up into Canada,

to the edge of the frozen Yukon.

The Rockies are 3,000 miles long.

Five times the length of Britain.

There's so many mountains,

many don't even have names.

This is a world of unknown peaks

and hidden valleys.

The last great sanctuary of the iconic animals of North America.

Buffalo still roam free...

..and grizzlies raise their young.

It's winter.

Minus ten.

The days are short.

But before the animals go into lockdown,

one event is about to stir the Rockies.

It's all down to Bighorn sheep.

Normally docile, but today,

a scent is in the air.

And it's turning the males into warriors.

It's the most important moment in their year.

All the males are picking up the scent...

..drawing it up into the roof of their mouths.

Analysing the smell.

The females produce this particular perfume only when they're in heat.

Each female is fertile for just two days.

Not a chance a red-blooded ram wants to miss.

But to get to mate, they first have to fight the other males.

It begins

with pushing and shoving...

..but quickly goes below the belt.

Goading each other, seeing who's strongest...

..who's up for it.

And then the fight is on.

This is their one chance.

They've got to take it.

The horns can weigh 30 pounds.

As much as the rest of their bones.

It's the biggest rumble in the Rockies.

It echoes for miles around the mountains.

Clashing horns with eight times the

force that would fracture a human skull.

Other creatures would get brain damage.

But Bighorns have double-thickness skulls to soak up the shock.

The losers are left with a sore head.

They'll have to wait a whole year for another shot at mating.

The victors get the females.

They've seized their chance, and won.

And choosing that perfect moment

is the secret to success throughout the Rockies.

And that's for one simple reason -

the weather here is more changeable than

any of the other great mountain ranges.

The greatest daily temperature swing in the world

was recorded in the Rockies,

dropping 56 degrees Centigrade from one day to the next.

But the seasonal swing is even bigger.

The summers are scorching and dry.

Every year, 700,000 acres go up in smoke.

Temperatures soar to 40 degrees.

But in the winter, avalanches rip down at 80mph.

There's 100,000 every year.

Temperatures plummet to minus 40 -

cold enough to freeze the mercury in a thermometer.

By midwinter, the world is frozen solid.

WIND WHISTLES

BIRD CALLS

Diamond dust.

Ice crystallised by the frozen air.

Winter can be beautiful.

But brutal.

Winds reach 200mph.

ANIMALS GRUNT

It can snow six feet in a day.

For most, winter is a time of hardship and suffering.

But here in the far north of the Rockies,

it's the perfect moment for one creature.

The Wolverine.

Most people spend a lifetime here and never even glimpse one.

He feeds on the frozen bodies of animals killed by winter...

..and preserved in nature's freezer.

His nose can detect food buried 20 feet deep.

Other animals follow him around hoping to steal a meal.

But carcasses are few and far between.

Each day, he must scour the mountains for scraps.

Determination pays off.

The frozen remains are as hard as iron,

but specially adapted teeth tear them open.

Ravens sound the dinner bell.

And it brings the mountains' top predator.

HOWLING

The Wolverine has to act fast.

A hungry wolf pack could kill him.

It doesn't take long for wolves to devour a carcass.

He melts back into the wilderness,

always searching for another chance.

Seizing the moment is crucial for

all creatures that live in the Rockies.

And that's especially true of one unique animal.

The mountains call us,

but we're not built to live above the clouds.

We, most of all, must gauge the conditions perfectly.

For those with the courage and the judgment,

the prize is the freedom of these mountains.

For some, the draw of the Rockies is so strong

they need to go further and higher.

I mean, ALL mountains have a moodiness to them,

have a personality.

But the Rockies, the Rockies might take the cake.

Hillary O'Neil is a professional mountaineer and skier.

She's climbed Everest and led expeditions

to mountains around the world for 15 years.

But her home is Colorado,

in the southern Rockies.

It's not for the beginner, they're steep mountains, they're rugged.

It keeps you on your toes.

I think I could spend ten lifetimes here

There's one mountain in particular she wants to climb.

And now, in late winter, it's the perfect moment.

Mount Sneffels.

The highest peak for miles.

At 4,300 metres high,

the air's 40% thinner than at sea level.

And the winds can blow over 100mph.

She's set herself a task to climb it,

and then, for the very first time,

she will ski down the treacherous north side,

down a steep gully called The Snake.

I mean, there's, you know, lots of catchphrases

about the Rocky Mountains.

And the one that always kind of sticks in my head is, you know,

"If you don't like the weather, wait five minutes and it'll change."

For me, it makes me want to go out in the mountains every day,

because I think it's going to be different every day. And sometimes,

sometimes I think the mountains around here

are warm and welcoming, and other times you're like,

"God, I just hope they let me go and let me out of their grasp,

"and I can go home!"

It's a long slog to the summit.

With the air getting thinner.

And the snow getting deeper.

I often feel threatened when I'm up here.

I think it's a good thing to feel fear cos that means you're pushing

yourself a little bit. And that makes you feel alive

and, yeah, I would take that any day.

There's no time to stop at the summit.

She quickly abseils down to the start of the gully.

Every minute, the wind is picking up.

There's no time to waste.

SHE PANTS

These mountain gullies act as funnels for avalanches.

As she approaches the bottleneck...

..the snow is getting more and more unstable.

Oh...

Woo!

The hard work done,

now she can claim her prize.

When I go and do something new in these mountains,

it feels pioneering,

in a modern way.

And I think that is a lot of the spirit of the people

that still live around these mountains.

The Rockies have always attracted pioneers.

Thousands flocked here in the 1800s.

Some made fortunes.

For others, the timing was wrong.

Mining towns,

abandoned after the gold and silver ran out.

Farmers were also lured west with the promise of cheap land.

Early March,

and the last snow of winter falls on an abandoned ranch in Montana.