Original subtitles

(upbeat music)

There are places in Greater Yellowstone

where snow never melts,

or at least it never used to.

These remote ice patches hide ancient artifacts

perfectly preserved for thousands of years.

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Now, our warming climate is exposing these fragile treasures

and soon there'll be lost forever.

Once it's gone, it's gone.

The longer it's melted out of an ice patch,

the more it will be decayed.

Every summer more clues

about the early people that lived here come to light

and the stakes get higher.

It's a race against time (water trickling)

to save our hidden history from melting graves.

Each time we get one step closer

to the actual human being,

we have an incrementally improved understanding

of how attuned they were to their environment,

and their ability to engage with it.

The native people really were everywhere

on this landscape.

They were at 10,000 feet over 10,000 years ago.

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When snow and ice accumulate at high elevations

they never completely melt, even during summer.

They build up over thousands of years.

Glaciers move, they are conveyor belts

by definition how they operate

and ice patches tend to be static features.

They don't move, or if they do move, they don't move much.

The artifacts remain close to the same spot

where they landed.

These are objects that were

in the middle of their use of life and then are left

as a result of whatever actions were taking place.

The animals and humans

left traces of their presence

that have remained perfectly preserved.

Each is a rare window into the distant past.

The things that are the objects of material culture

represent a great deal of time, energy and effort

on the part of the person who manufactured it,

or for whom they traded.

And Yellowstone's ice patches

reveal organic relics

including Big Horn Sheep skulls

that are over 5,000 years old.

(water trickling)

Ice patch archeologists are careful to respect

the cultural significance of whatever lies beneath,

and to consult with the local tribal representatives.

Well, archeology is very important

to preserving American Indian heritage,

because we need to continue to learn about our story.

And we need to continue to tell our story

in a way that is more truthful,

that is more honest,

that is more human.

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We do not excavate at ice patches.

The materials that come out of ice patches

are all being released by what we generally refer to as

atypical melting.

Stone points and tools

shed light on how early people hunted for food.

We could look at this entire plateau

and do things like look at every one

of the obsidian artifacts,

and where did those obsidian artifacts come from?

They came from volcanic rock

that was quarried from the obsidian cliffs.

And some entered a trading network

that extended from British Columbia to the Midwest.

The most prized was Yellowstone obsidian,

and that obsidian was also easily harvested

and therefore easily tradable.

And I believe archeologists have placed it

as one of the most traded objects in world history.

And we find it an all four corners of the continent.

At the highest altitudes in Greater Yellowstone

stone tools make up most of what scientists uncover.

90%, 95% of all the archeology that we deal with

is comprised of this inorganic element.

And yet that only really likely represented

about 5% of the total culture of the folks

that you might be interested in studying.

Yellowstone's early people

interacted with groups outside their homelands,

and that also indicates a sophisticated culture.

The Greater Yellowstone area groups

were more sophisticated than they're commonly portrayed.

These people were masters at understanding the landscape,

where to be at certain times of the year.

They understood the movement of the animals.

Oftentimes we consider

people of the Greater Yellowstone area to be nomadic.

The fact of the matter is

all of their movements were planned.

More proof of this is found in the bones,

hides, and remnants of early campsites

emerging from the ice.

The collection is representative of what's going on

in the Greater Yellowstone.

One bone even show signs

that an early American split it open to enjoy the marrow.

The organic matter

reveals details about the daily lives

of Yellowstone's earliest people

beyond their hunting skills.

And so that's where these

uniquely preservative environments like ice patches

provide this entree to understand the past

in a much more robust way.

The wooden shafts, sinews, and woven pieces

are of particular interest to Craig.

The wood is not haphazard.

You make very careful selection

of the types of wood that you're using for your dart shafts,

for your main shafts.

You make careful selection on the types of sinew

that you would use for lashing,

the types of feathers that you would use for fletching.

But beyond following their prey,

why did early people travel to such high elevations?

It's an escape from hotter temperatures down low.

And we see that folks likely went to Alpine environments

to engage in provision, not just for food subsistence,

but I think also spiritual subsistence.

So this is another one of these things where

again we don't have all the answers,

and that's kind of the fun part of this work

is that we have this opportunity

to explore things that are not easily identified.

(spiritual music)

Archeologists and tribal representatives

work together to preserve these pieces of pre-history

before it's too late.

I think that they went to the mountains 10,000 years ago

for the same reasons that we go to the mountains.

The ice patches reveal

the ways humans used the high altitude environments

beginning about 10,000 years ago.

The folks had a complete and total understanding

of how those environments operated,

where they could expect animals to be present

at certain times of year,

but also reasonable source of water.

All of these things suggest

that these are people that are very much in tune

with their environment.

For thousands of years,

large mammals have migrated up to the ice patches

during summer to escape heat and biting insects.

Native people understood that animal movements

like bison, elk, and deer

were very much closely aligned to the wind.

And it's the wind that carries the smell of the grass.

And it's the smell of that grass

that causes those animals to move.

Early people strategically followed their game

into the high mountains.

We've got numerous instances of bison

in association with ice patches,

but the Big Horn Sheep have the most demonstrable evidence

for having been hunted at those locations.

Once an animal reached the ice,

it was difficult for them to flee the hunters.

When the hunters and their families returned to the flats

they left behind clues about their time near the ice.

That could be a bark, like a cherry bark.

It's twisted leather, it's not braided,

it's maybe more simply twisted.

We've done ancient DNA on that, that leather.

And I was expecting it to be sheep given the context,

high up in the Alpine, but it turns out it's elk.

Snow falls every year in these spots,

and when the top layer melts during summer

it compresses the layers underneath.

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This results in snapshots into the past

that span thousands of years.

I believe there to be permafrost underneath ice patches.

Ice patches can be quite thin in some instances,

and only a few meters deep,

and they can contain archeological record

that's 6,000, 7,000, 10,000 years old.

Permafrost below the ice patches

would assist preservation,

but it won't be much help if the surface ice melts.

(water trickling)

Yellowstone's ice patches also tell the climate story

from 10,000 years ago through today.

And now the biggest thaw in recent history

is releasing the long frozen items at an alarming rate.

Few scientists specialize in ice patch archeology.

I suspect you're probably looking at

less than 25 folks worldwide

that are really actively engaged in ice patch archeology,

and actually doing field research.

Ice patch research and recovery

is very different from what we typically imagine

archeology to be.

These are places that most of the year

are in heavily snow-covered areas.

And consequently, the window in which

we have access to the materials is narrow.

The window is only about two weeks per year,

and conditions are never predictable.

Google Earth, with its high resolution satellite image,

has helped to refine survey locations.

The scientists also fly aerial reconnaissance

over 24,000 square miles searching for ice patches

that seem most likely to yield artifacts.

We can grade those ice patches based on their potential.

In the high mountains,

the team searches for any ice patches

that appear to be retreating.

And then for anything sticking out of the surface.

Dr. Craig Lee recovered

the oldest intact wooden artifact

ever found in a Yellowstone ice patch,

a Birch dart shaft with personal markings near the tip.

The tool even has ownership markings.

This is a large instrument,

probably around four feet long,

and it was notched by the designer, by the maker,

with three little marks.

And the maker of this was able to

imbue his power into this dart.

And also to allow others to know that this belonged to him.

Radiocarbon dating

showed it to be an astonishing 10,300 years old.

All living things are actively incorporating

radioactive carbon that is

omnipresent throughout the atmosphere,

and throughout the biosphere into their system.

Based on the amount of radiocarbon

that is left in an artifact,

we can tell you how long that thing has ceased to be alive.

The scientists must recover the artifacts first

but Earth's clock is ticking.

The ice patches have shrunk by 50% over the last year alone.

(water trickling)

According to NOAA,

every year our planet is getting warmer.

Two places where the effects of global warming

are clearly evident are Montana's Glacier Park,

and the Greater Yellowstone area.

Higher temperatures in the Alpine regions

are problematic for wildlife and plants,

and disastrous for the organic ice patch artifacts.

Glaciers maybe track a decadal average,

whereas ice patches can really respond in a given year.

You really have to be there within the year

in which that material melts out.

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This never before seen chapter in human history

is in danger of being lost forever.

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