(gentle music) (birds chirping) >>The Appalachian Mountains, a storied landscape spanning hundreds of millions of years.

To the human eye, the Appalachians appear steadfast, immovable, but in fact, this powerful expanse has been in constant transition for millennia.

Tucked within its most ancient folds lies Shenandoah National Park, a living world.

(gentle music) Home to over 200 species of birds, 50 kinds of mammals, nearly 40 types of fish, and over 25 species of amphibians, this diverse ecosystem fuels the region's continuous evolution, with each and every inhabitant playing a crucial role in Shenandoah's vitality.

Though this dynamic may often go unnoticed, three major forces of change propel this ecosystem, formations, migrations, and transformations.

Together, they continuously create and shape the wilderness of Shenandoah National Park.

>>Production funding for Shenandoah was provided by John McGurl, Michelle Gluck, and the Hacker family, and by... (lively music) >>We are the Southern Environmental Law Center.

At SELC, we take on environmental challenges in court, in the halls of government, and in communities across our region.

For more than 40 years, SELC has worked to help protect our environment, whether it's our rivers, our air, our public lands, wildlife, or community health.

More information at selc.org.

>>Also by the Chrisman Family Foundation, Fred W Scott Jr, and by... (birds chirping) >>The smallest acts can bring about the most dramatic formations, quietly sparking rebirth throughout this 200,000-acre expanse.

Unaware of his own impact, Shenandoah's largest wanderer goes about his day, leaving behind more than just footprints.

With winter approaching, this black bear wastes no time, eating everything he can while the good times last, even if this means going to great heights.

Like his peers, he's an expert climber, stripping entire vines of wild grapes, which turns out is just what the vines need.

Eagerly filling his belly, he swallows the fruit whole, seeds and all.

Lured by the sweet scent and his hunger, the bear suddenly finds himself in a sticky situation.

The higher he goes, the thinner the branches.

But the grapes look very tempting, the risk may be worth it.

(gentle music) On second thought, maybe not.

With a sense of smell 2,000 times more effective than humans, he'll find other spots for sustenance.

As winter nears and food becomes increasingly scarce, this bear wanders for miles in search of his next meal.

(gentle music) Moving about the forest, he carries the vines' seeds to far-off locations, spreading them as he goes about his business.

As a keystone species, this bear quietly shapes the forest, sparking plant regeneration wherever he roams.

But the black bear's vital role almost disappeared.

When Shenandoah was founded in 1935, few black bears roamed the forest.

Thanks to federal protection, hundreds thrive here today, like this one.

As winter takes hold, black bears across the park fall into states of deep sleep called torpor.

Though easily awakened, their heart rate and breathing decrease, allowing them to survive for months on body fat alone.

And while time seems to pause in their world, the seeds they've left behind take root, waiting for their moment to rise again.

As the warmth of spring seeps into the forest, seeds and dormant roots begin to stir, sending new growth upward.

At the same time, animals emerge from their winter hideaways in need of sustenance.

For many small-winged creatures, the search comes easy.

With over 850 species of wild flowers blooming in Shenandoah, springtime offers a feast of color and opportunity.

(gentle music) Unlike some food sources, flowering plants do not hide, rather, they invite attention.

Amidst this plant life diversity, wild bergamot stands out.

Growing as high as five feet, its fragrant petals and rich source of nectar lure visitors in close, offering nourishment in a simple trade, pollination.

For millennia, this pollinator powerhouse has evolved an interspecies bond with a wide variety of pollinators, a delicate partnership where each depends on the other to survive.

Among wild bergamots' most majestic visitors is a butterfly so iconic, it holds the title of Virginia's state insect, the eastern tiger swallowtail.

With less than two weeks to live, this butterfly spends his brief adulthood focused on mating.

And wild bergamot's nectar provides the vital energy he needs to make the most of his limited time.

Evolved for butterflies like him, he inserts his long proboscis into the tubular flowers, extracting the nectar from deep within.

As he and his peers find their nourishment, the flower's pollen sticks to their bodies.

Flying from bloom to bloom, they unwittingly kick off another miraculous formation in Shenandoah.

(lively music) Hermaphroditic by nature, wild bergamot holds both male and female parts in each flower.

As the butterflies visit, they transfer pollen from the flower's male features to their female centers, sparking seed production.

Here, wild bergamot's formation begins once more, ensuring life will rise again next spring.

(gentle music) While Shenandoah's landscape bursts with new beginnings, the roots of its ancient history remain hidden from view, far below the surface.

Deep below the Shenandoah Valley, beside the park's rolling mountains, lies a vast network of nearly 100 limestone and dolostone caves.

While these ancient caverns are some of the oldest along North America's East Coast, the story of the Appalachian Mountains begins long before their formation.

A billion years ago, all of Earth's continental crust clumped together to form a supercontinent called Rodinia.

Across hundreds of millions of years, deep geological activity drove the tectonic plates apart.

In this new opening, the salty waters rushing in formed the new ocean called Iapetus, which flooded what's now the Shenandoah Valley.

The distinctive limestone and red clay formation seen today followed this tumultuous era.

These exquisite bejeweled chambers hold rich minerals, some born from the ancient ocean's depths where tiny sea creatures once settled.

Though caves like these seem static, in fact, they are living entities, always changing, but on a timescale very different from our own.

Over 50 million years after the formation of the Iapetus Ocean, the tectonic plates shifted once again.

This time they collided, thrusting the ancient rocks upward and giving rise to the Appalachian Mountains.

Some evidence suggests they may have reached as high as 26,000 feet above sea level.

The present-day Himalayas offer a sense of the peaks' towering appearance soon after their formation.

But over hundreds of millions of years, erosion has weathered the Appalachian Mountains into the gentle peaks we see today, stretching from Alabama all the way to Newfoundland, Canada.

(gentle music) Though today they only reach 4,000 feet above sea level, the iconic Blue Ridge Mountains of Shenandoah still define Virginia's horizon.

(birds chirping) Over the ages, one ancient creature has evolved in the peaks of this shifting landscape.

Seldom seen, this resident makes a rare appearance, the Shenandoah salamander.

In a region home to the highest diversity of salamanders on the planet, this species is one of a kind, found nowhere else on Earth.

(lively music) With his distinctively narrow yellow stripe, this salamander emerges from the dark, hunting for flies, beetles, and other unsuspecting prey.

But he can't stray too far.

As one of the most geographically restricted vertebrates in the world, the Shenandoah salamander has adapted to a tiny niche atop only three mountains in Shenandoah.

Often bathed in fog, his high-elevation home provides a cool, wet environment, essential for his survival.

(gentle music) With no lungs to breathe, his moist skin lets oxygen diffuse through his pores and into his bloodstream so he can respire.

But as climate change drives fog to higher altitudes and their fragile habitat continues to shrink, the Shenandoah salamander has become federally endangered, but this creature's will to survive remains strong.

Today he focuses on his more immediate goal, finding food.

Throughout his search, he must maintain his body temperature.

As the hot midday sun breaks through the clouds, he must retreat underground to prevent his skin from drying out.

There, the cool moisture of the soil offers much needed relief and a safe hideout until the fog returns.

For millennia, people have also sought refuge in these hills.

Indigenous Americans first arrived in this region over 9,000 years ago.

However, in the mid-1700s, European settlers displaced them and began moving to Shenandoah, establishing farms and developing mining industries.

As the early 20th century unfolded, rapid industrialization overtook the whole country.

But along with urban expansion, many leaders recognized the importance of preserving America's natural beauty for future generations.

In 1916, President Woodrow Wilson established the national park system for this very purpose.

Over 10 parks and monuments across the country soon became part of the fledgling government agency.

However, almost no national parks existed on the East Coast.

So in 1924, the NPS began the search for an area of stunning beauty that would bring the national park experience to the more populated east.

Local businessmen and politicians jumped at the opportunity to boost tourism in Virginia and lobbied Congress to choose the majestic Blue Ridge.

And in 1926, Congress authorized Shenandoah National Park.

However, establishing a new national park in the Blue Ridge Mountains came with significant sacrifice.

At the time, the land was mostly privately owned and provided homes to families and their businesses, schools, and churches.

The Commonwealth of Virginia condemned the land.

Using eminent domain law, it acquired about 160,000 acres and donated the land to the federal government for Shenandoah's formation.

Throughout the early 1930s, this land seizure displaced nearly 500 families, including the mother and grandparents of Jim Lillard of the Madison County Historical Society.

>>My mother was 14 years old when they left the park.

My grandfather had 154-acre farm and he had 13 kids.

My mother could remember it well, of course, I got all my stories from her.

Everyone had a story, you know, about what happened when their family come out of the park.

You could see where it was a very big change in people's lives, they had to move and start all over.

A lot of very strong people, and all they knew was work.

They liked the dark to make a living.

President Hoover did not allow alcohol because of the prohibition, it was illegal, but he said it was moonshine in every stump hole in the mountains, so you could buy, you could get all you wanted.

They made moonshine out of apples, apple brandy was the best, and you make it out of any fruit.

>>Did you ever make any moonshine?

>>I don't want to answer that.

(both laugh) It was tough on some people, really was.

The thing is you had to go whether you wanted to or not.

And you gotta remember the depression was going on, and most of these people didn't own nothing in the stock market, the only stock they had was pigs and chickens.

My grandfather, he got enough to buy him another farm, bigger than what he had, down out of the park.

So it was good stories and bad stories.

Most of the house was burned because they didn't want 'em coming back to live in the houses.

It was eight counties that lost land to the park, and since then, all eight counties have a memorial, which I'm very proud of.

And most of 'em are made on the order of a chimney because the only thing left was the chimneys.

There's something to recognize their sacrifices to leave all this land for the wonderful park we had.

So I love walking in the park and I like going with other people, finding their home sites of their ancestors.

You can see the old chimneys where the house were, and the graveyards, and remember that people here that got displaced.

>>In July of 1936, President Franklin D Roosevelt officially dedicated Shenandoah National Park, and the public loved it.

(gentle music) The saying goes, the only constant is change.

And as residents come and go, the mountains' interconnected ecosystems continue to evolve, sustaining life here and far beyond.

(soft music) Shenandoah's unique position along the crest of the Blue Ridge Mountains taps into the life force that permeates throughout the park and the planet, a vital intercontinental corridor.

The park links ecosystems from northern and southern hemispheres, providing a forested refuge for numerous migratory birds.

As these international travelers come and go, the forest's soundscape shifts with the seasons, shaped by life unfolding in the canopies between earth and sky.

Of the 200 bird species that thrive in Shenandoah, over 3/4 find refuge here only temporarily to breed and rest during brief journeys to Appalachia's higher elevations and distant voyages along the Atlantic flyway.

While summering in these mountains, one species is making the most of it, the American redstart.

Using the forested canopy, this mother-to-be is building a home for her young, away from the elements and from predators.

(soft music) Working with purpose, she gathers grass, stray animal hair, spider and caterpillar silk, weaving a nest that disappears into the environment.

(gentle music) Compacting these materials with her body, she creates a solid structure that will protect her eggs.

(gentle music) After almost two weeks of incubation, life bursts forth.

(gentle music) With four more mouths to feed, a mother's work is never done.

The sunlight, piercing through the open canopy, gives her great visibility to hunt for insects below.

But as she leaves the forest shelter, she must remain alert.

Up here, she shares the airspace with far more formidable hunters, as raptors are also hunting for prey.

With eyesight up to three times sharper than our own, this peregrine falcon can spot prey from over a mile away.

A carnivore, she targets another bird flying above the canopy and zeroes in.

From high above, this hunter takes a breathtaking dive known as a stoop, plummeting at speeds over 200 miles per hour, making the peregrine falcon the fastest animal on earth.

With an average 35% hit rate in hunting, she knocks her prey out of the air.

Tearing it apart, she prepares the meat to feed her nestlings.

Unlike many other bird species here, the peregrine falcon takes refuge on the high ledges above Shenandoah's forested canopies.

This remote elevated perch lets her hide in the light and provides incredible visibility for her next hunting expedition.

But these same cliffs pose a daunting challenge for the offspring.

Just getting this far is no simple feat.

Over 1/3 of Peregrines don't survive their first year.

And at 42 days old, this young survivor is going out on a limb.

(gentle music) For this first-time flyer, the cliffs are high (gentle music) and the gusts of wind strong.

Simply spreading his wings helps him get a feel, (gentle music) but the bravest step means taking the plunge.

Airborne, at last.

Over the next couple of months, he will hone his flight skills.

Learning to ride the air currents to perfect his hunting technique will soon provide the key to his long-term survival and prepare him for his own upcoming migration.

Birds aren't the only species that pass through the wilds of Shenandoah.

One of the greatest human journeys on earth traces much of the ancient spine of the Appalachian mountains, a nearly 2200-mile odyssey traversing 14 US states, from Georgia to Maine.

(soft music) Hiking the Appalachian Trail represents more than a mere physical challenge.

This once-in-a-lifetime pilgrimage can reconnect us to something older, deeper.

Traversing the 100-mile stretch through Shenandoah, hiker Mary Wilson continues her months-long journey alongside her guide dog Thor.

If she succeeds, she'll become the first blind woman to complete the Appalachian Trail.

>>I definitely appreciate nature in a new way since becoming blind.

I'm so much more in tune to the smells and the sounds and just the way the earth feels beneath my feet.

I love to hear the wind through the trees, the birds chirping, the woodpeckers, animal scurrying through the forest floor.

(soft music) We are a team of two, but when we're hiking, we're hiking as one and he's an extension of myself.

When I'm hiking, I can't even tell you where my hand stops and the harness handle begins.

I'm getting so much feedback about the terrain, all through that harness handle.

Good boy, Thor.

As a blind person, it's very hard to keep a straight line of travel and to know where the path is.

Thor, forward.

He keeps me on track, going in the direction I wanna go.

(soft music) I started this journey for several reasons.

I wanted other blind and disabled folks to know that the outdoors is for them too.

Just because you have a disability, your life doesn't end, you're just doing it in a different way than you might have before.

(gentle music) I think nature is healing because it's where we're honestly meant to be.

It's just magical.

(soft music) The more I experience it, the more I realize I really, really need it.

(birds chirping) >>Perhaps Shenandoah's most magical travelers come with a little flutter.

(lively music) The monarch butterfly, the only butterfly in the world that makes a two-way migration across North America.

But unlike birds, this journey takes several generations to complete.

Starting in spring, monarchs migrating northward from Mexico, simply don't live long enough to make the whopping 6,000-mile journey as far north as Canada and all the way back again.

To make the transgenerational journey, this monarch makes a crucial stop here in Shenandoah.

Like the other monarchs, she can't just stop anywhere to lay her eggs, she needs milkweed, and luckily for her, Big Meadows is bursting with them.

She can thank indigenous hunter gatherers for this sanctuary.

Starting around 9,000 years ago, they cleared this area, turning it into a hunting ground.

(soft music) From this land once home to the Monacan, Manahoac, and Massawomeck, endures a name whose origins remain a mystery, Shenandoah.

Some translate it as beautiful daughter of the stars.

(soft music) Today, urban development and pesticides contribute to the sharp decline of monarchs, but beautiful havens like these help ensure its survival.

Federally protected from encroachment, the rich soil and wide-open space provide the perfect growing conditions for milkweed and the monarchs.

Though the plants are poisonous to most creatures, this butterfly lays hundreds of eggs on them before she dies.

Milkweed's toxicity doesn't just defend her eggs from predators, it also kick-starts a powerful defense strategy.

When the caterpillars hatch, they begin feeding on the plant.

Most animals couldn't stomach it, but monarchs have evolved this adaptation for a reason.

By absorbing the toxins, they become poisonous themselves.

Their black, yellow, and white stripes send a clear message to potential predators, stay away.

(gentle music) This chemical armor remains with them through their metamorphosis into adult butterflies.

(gentle music) From here, the monarch's journey continues, led by the next generation.

But how these torch-bearers know to navigate these specific flight paths and when requires an extraordinary sixth sense, a kind of biological compass that uses the sun's position and their own circadian clock to guide them on their epic transgenerational voyage.

(soft music) (birds chirping) Rivers cut through mountains by force and persistence.

As a master of transformation, water continuously changes form, shaping both land and life in its path.

Throughout the Mid-Atlantic, heat from the sun primarily causes water to evaporate and transform into gas.

As winds carry the water vapor up the mountain slopes of Shenandoah, the air cools.

Vapor condenses into tiny water droplets, forming oceans of clouds.

In this mist, countless creatures thrive, but once the droplets become too heavy for the clouds to hold, (thunder rolls) they fall.

(gentle music) The raindrops move through soil and rock, making their way to streams and gather into rivers.

(gentle music) These fluid paths carry minerals and nutrients everywhere, nourishing the forests, valleys, and marshes, supporting over 3,600 species of plants and animals, from Shenandoah, all the way to the river's ends.

(gentle music) As gravity guides these rivers toward the ocean, the water connects far-flung ecosystems as they converge on the Chesapeake Bay, the largest estuary in the country.

(gentle music) From the Blue Ridge Mountains to the Atlantic Ocean, water has the power to transform life itself.

But another even more mysterious entity follows the water's path from the ocean up to Shenandoah, one that must transform itself to complete its own journey.

For this elusive Shenandoah native, the transformation begins over 1,000 miles beyond the coastline, in the middle of the Atlantic Ocean.

Here lies the world's only sea defined not by land boundaries, but by ocean currents.

In the Sargasso Sea, microscopic larvae, invisible to the naked eye, hatch in droves and drift in the ocean waters for about a year.

Eventually, the currents propel them to the American East coast as they approach the shoreline, the faintest presence of fresh water prompts these larvae to transform into transparent noodle-like creatures and develop fins.

Rushing inland, the surge of fresh water sparks the development of pigment, providing essential camouflage from predators.

Over the course of another year, they double in size as the freshwater environment transforms their bodies.

Lulled by the call of home, the determined creatures swim upstream as high as 3,000 feet above sea level.

At last, in the upper reaches of the Rapidan River, they transform into long snake-like creatures.

This is the American eel.

As the only freshwater eel species native to North America, they hunt in these rivers for up to 40 years.

But one thing they won't do up here is reproduce because they are neither male nor female.

Only as the years go by, after growing two to three feet long, does this one even develop a sex.

At this stage, her eyes enlarge by 10 times, her fins broaden, and her skin color changes yet again to silver.

This metamorphosis prepares her for her final journey.

What drives her remains unknown, but she instinctively travels back downriver to the Atlantic to the exact place where she was born.

How she knows where to go continues to be a mystery, but once there, she congregates with other eels hundreds of feet deep in the water where they spawn.

The eels' journey ends here where they die after mating, ending a lifecycle that can last almost half a century.

But as their eggs hatch, the circle of life sparks the next generation of eels to rise again, back home to the mountain streams of Shenandoah.

As life transforms within the contours of the mountains, the landscape itself also constantly changes, shaped by the rhythms of the seasons.

When winter transitions to spring, Shenandoah's lush forest canopy unfurls.

The increased amount of daylight drives ongoing change in plants and animals alike.

The longer days incite hormonal shifts in male deer, jump-starting another traumatic change, antler growth.

Abundant vegetation also fuels this surge, leading some adult bucks to grow antlers an inch and a half per week.

Velvet composed of skin and blood vessels envelopes the antlers, delivering the nutrients and oxygen needed for this rapid growth.

(soft music) But after the summer solstice, as the days shorten, the blood flow to the antlers slows.

The velvet dries and falls away, revealing hardened bone.

By September, the male's antlers have fully formed, just in time for battle.

(soft music) Shorter days unleash a rise in hormones, driving bucks to aggression as they assert dominance to attract those.

As winter nears and mating season ends, hormone levels and antlers drop.

The deer's fur coats grow thicker and warmer as they search for shelter.

Daylight continues to fade and a deeper shift takes hold.

While many animals settle in for their winter's sleep, deer cannot shut down their hunger.

To survive, they slow their movements, conserving enough energy to make it through the long, cold months ahead.

Without every creature's essential adaptations, life could not survive Shenandoah's seasonal transformations.

(soft music) Survival means resilience.

(soft music) Whether life is fleeting eating or spans a thousand years, the towering eastern hemlock lives for centuries and can grow up to 160 feet.

At these heights, they shade river streams, shelter creatures, and shape the park's entire ecosystem.

But even giants can fall, and sometimes all it takes is something almost too small to see.

Here, a tiny invasive insect is laying siege, transforming the ecosystem in its path, the hemlock woolly adelgid.

Spreading quickly, the microscopic insects hatch from woolly masses.

Clinging to hemlock branches, they feed on the trees' internal food sources and drain the trees of life.

Accidentally introduced from Japan via global trade, these tiny invaders have infested the entire span of the Appalachian Trail and beyond, leaving skeletal remains scattered across the hillsides.

(gentle music) Lacking natural predators, the adelgid has spread unchecked, wiping out a staggering 95% of Shenandoah's hemlock trees.

To counter this, the National Park Service's biological technicians are introducing natural predators, species that have evolved alongside the pest in its native range, like the Laricobius beetle, a tiny but powerful ally in the fight to save hemlocks.

>>It's always a little scary to introduce a non-native to control the non-native, but these beetles are very specific, they feed entirely on the adelgids.

And here at our park, we waited a long time just to make sure it was safe.

Without some kind of control, we feel like we're gonna lose all our hemlocks.

They are so important to our ecosystem.

They're classified as a keystone species.

If you take the keystone out of an arch, the whole arch falls apart.

Our middle school group came out and we were emphasizing how important the hemlocks are.

If we lose our hemlocks right here, it's going to change the nature of this little ecosystem.

And so one of the students spoke up and said, "Yeah, we need a lot of duct tape to put it back together or keep it together."

And another student spoke up and said, "Yeah, the Lari beetles are the duct tape for the hemlock ecosystem," which I thought was very insightful and a good way to put it.

If we don't do something, we're gonna lose our hemlocks and things are gonna really change in our forest.

The hemlock woolly adelgid, they'll be here, I think forever.

But we hope eventually there will be that balance established where we'll have enough natural controls to keep them in check.

We do see some regeneration, I see little seedlings coming on.

We feel like with ongoing efforts, that percentage of our forest will be hemlocks in years to come.

>>Still, in nature, nothing lasts forever, but in the complex web of life, death is not an end, it's a transformation, a transformation which creates new beginnings.

(gentle music) Throughout the forest floor, hundreds of species of bacteria, slugs, and earthworms work together in silent concert.

As nature's recyclers, the forest microbiome breaks down the dead, transforming decay into rich organic matter, regenerating and nourishing life throughout Shenandoah.

Conducting this profound resurrection, a sprawling life form operates, just out of sight.

A vast network transports, recycles, and connects the entire underground community to sustain the world above, all thanks to the intricate work of fungi.

Creating a symbiotic relationship, some fungi colonize live plant roots underground, delivering vital nutrients that foster the plant's growth.

In exchange, the fungi receive energy from the plant to further their own reach across the terrain.

Connecting with almost 90% of all plant species, some fungi link to multiple species at once, enabling plant-to-plant communication.

Through this complex fungal network, plants send chemical signals, warning others of potential threats, sharing nutrients, and even releasing chemicals to influence how neighboring plants will grow.

All life in Shenandoah rests on this hidden subterranean backbone of the forest, where energy left behind in death changes shape and powers new growth.

From these tiny foundations, life rises, creating even greater webs of life and death.

At Shenandoah National Park, constant change connects the past, the present, and the future of life on Earth.

Ages and eras move like a shadow during the day, often unnoticeable in the moment, as the forces of change propel Shenandoah's ever-evolving ecosystem.

(gentle music) Formations, migrations, transformations, each a step along the winding journey of nature that may one day lead to an understanding of the greatest story of all, life itself.

>>Production funding for Shenandoah was provided by John McGurl, Michelle Gluck, and the Hacker family, and by... (lively music) >>We are the Southern Environmental Law Center.

At SELC, we take on environmental challenges in court, in the halls of government, and in communities across our region.

For more than 40 years, SELC has worked to help protect our environment, whether it's our rivers, our air, our public lands, wildlife, or community health.

More information at selc.org.

>>Also by the Chrisman Family Foundation, Fred W Scott Jr, and by... (soft music) (gentle music) (lively music)