It just sounded like a big ol' thunder, like, roar, big ol' roar, you know.

Like, you could hear it for a couple of miles away.

So there was always a lot of people here, a lot.

Oh my god, there was so many, 'cause you start in spring and fish all the way until September.

And I would smell the salmon, you know, and watch 'em coming up, over the falls, and feeling the mist on my face.

We refer to it as Enchuwana.

And what that means in our language is the big river.

It's not a big river or it's not big rivers, in general, it's the big river.

A flat, watery plateau, now entombs the single most important site for fishing, trade, and culture for tribes across three states.

In 1957, the US government built the Dalles Dam, backed up the Columbia River, and buried Celilo Falls.

50 years later, many Native Americans remain bitter towards a government which took their homes, history, and very livelihoods.

In recent years, several tribes raised a serious new question.

Did the Army Corps of Engineers simply flood the falls or did it destroy them first?

Thomas Morning Owl had family who fished at Celilo and he has studied its history extensively.

There was a belief that there had been some major blasting that occurred at the Celilo Falls area prior to the inundation.

And then here, we have a computer presentation of the hydrographic survey results.

Now astounding new images reveal what's at the bottom of the river and could shake up what people thought they knew.

But to understand their significance, it's vital to understand river and tribal history.

This was the way it used to be, the great river of the West tearing toward the sea at Celilo Falls.

Tom McCall, before he was Oregon governor, produced a documentary called "Farewell at Celilo."

Celilo Village was a...

It touched on a litany of the government's broken promises.

First, in 1855, Congress promised in a treaty that tribes could continue to fish at all their usual and accustomed places.

But by the 1930s, America rushed headlong into the industrial age.

Mix and pour, mix and pour.

Day and night,... Damning rivers like the Columbia promised cheap, renewable electricity.

In 1937, Bonneville was the first Columbia River dam to be completed.

Thousands of anxious fishermen asked one question.

Could the salmon get over the dam?

The government claimed in its own films that fish ladders would keep the salmon moving to the native fishing grounds.

But to thousands of families along the Columbia, the king salmon means their very existence.

Chief Tommy can go on spearing the Royal Chinook in the tumultuous roar of Celilo Falls.

The salmon are going through.

But just a few years later, the government had decided it needed even more dams on the Columbia.

Bonneville and Grand Coulee are only the beginning.

Tame the hazardous rapids.

Government engineers say it can be done and waterfalls... For thousands of years, Native Americans had crossed tribal boundaries, traveled from across the Northwest, and had come together to fish and do business at Celilo Falls.

Soon, this entire cross-cultural center would perish.

The government also took back an island given by Congress in 1935.

It was a tribal burial ground and it, too, would soon be flooded.

Ancestors' remains had to be exhumed and transferred to shore, coffin by coffin.

Ultimately, the tribes settled with the government.

They accepted payments for the loss of their islands, homes, and the falls.

Except for one man, the last great leader at Celilo, Chief Tommy Thompson fought the construction of the Dalles Dam to the end.

He knew this was going to happen.

There was no way he could stop it, you know.

No matter how much he fought to keep the falls, you know, but the Corps eventually had won and it made him very sick.

Chief Thompson's granddaughter, Linda Meanus, posed with her grandparents above the falls, knowing they would soon be gone.

The photo became one of the iconic images of that era.

It kind of chokes me up.

My grandmother said that he died of a broken heart.

She's getting ready to dress him for a ceremony.

Linda's grandparents thought it was too painful and did not allow her to watch on the day Celilo disappeared.

His funeral at Celilo Village was to be conducted as he had directed, strict... Tom McCall's documentary paid tribute to Linda's grandfather just one week after the great chief died In Hood River, half blind and shrunken with age, Chief Thompson was spared the spectacle he had fought to avert.

He'd been a resident of Hanby's Nursing Home since 1955, growing feebler until a week ago, Sunday, he sank into his final sleep.

The Dalles Dam dropped its gates on March 10th, 1957.

It took less than one day, just a matter of hours for the hand of man to undo tens of thousands of years of natural history.

Thousands of outsiders flocked to the Columbia to watch the river back up.

Ada Colfax Frank, a resident still today at Celilo, saw it too.

I mean, a lot of people mourned over that.

I mean, I cried that day.

Before that they went to sleep and the sound of the river the sound of the river was in their head.

Just always incessant, that roar of the falls of just echo, echo.

And they said they went to sleep with that in their mind.

The next day, they were looking and the sound becomes smaller and smaller and smaller.

Pretty soon, they said there was no sound.

And all you could hear is just the wind.

And he said, then, the ladies cried.

Said that he could hear the people crying.

You could see the falls disappearing, the rocks disappearing, you know.

It was something to cry about because it was gone.

I was angry, even though I was just a little girl.

I remember how sad and how hurt I was when they flooded it.

I cried right along, you know, like those, like my grandfather.

But to hear that pain in the heart, pain of the voices, how that day just shook the world.

A lot of them never got over it.

A lot of 'em never got over it.

For the government, new hydro power was reason to cheer.

Vice President, Richard Nixon came two years later for a festive dedication of the Dalles Dam.

The tribes did not share in the revelry.

This was their celebration, it wasn't ours.

They conquered the Indians again.

In return for their falls and their land, the government built a new Celilo Village farther away from the river.

White man's progress, the lake, the highway had pushed the thinning remnants of Chief Thompson's tribe back against the wall of the gorge.

Most of the homes the government moved in were rundown discards from the army.

But the bottom line is we did relocate some residents and the housing just was not up to standard.

Finally, after years of conflict, relations have improved.

I'd like to welcome you all here today.

In May of 2008, the Army Corps of Engineers fulfilled its 1950s promise to provide safe, decent replacement homes.

There was many promises made to us and it took over 50 years for it to come true.

Real good day for our future.

What I mean by our future is our children where it's good for them to have these new homes.

They see a dream come true.

15 brand new homes and a new longhouse now stand in Celilo Village.

This is a ribbon-cutting for these houses but the project isn't over.

And then this project, in turn, contributes to other projects up and down the river that are so important.

It really turned out well.

But Army Corps Colonel, Thomas O'Donovan had one more enormously sensitive issue.

Tribes had challenged him, did the army Corps of Engineers dynamite Celilo Falls before the Dalles Dam backed up the Columbia River?

And I said, "Okay, I'll see what I can do."

And we went back and we did a little bit of research.

The colonel asked his staff to investigate.

A single snippet of historic film captures a massive explosion.

A handful of old photos show several more.

But most appear to be down at the dam's site, not upstream at Celilo Falls.

The others, you know, I asked them about it and they said, "No, there was actually blasting at Celilo."

The Army Corps kept digging and discovered an old memo from 1956.

In it, Elsie Thomas in house number two in Celilo Village complains that blasting nearby broke two windows and put a hole in a roof.

I have some experience in the demolition world, all combat engineers do, and you'd be surprised how far a concussion reverberation can carry and break a window.

A further note indicates the contractor fixed two homes with blast damage.

Finally, the Corps also unearthed an old design map with plans to excavate one small section of the river to make it deep enough for ship navigation.

Blasting was the common method to remove solid rock.

That excavation zone was 600 feet away from Celilo's signature horseshoe falls.

So my team came to me and said, "Look, we don't think "we blew the falls up."

And I said, "Well, that really isn't gonna cut it "in terms of sitting down with the tribes "and talking about this important culture resource "that it is for them."

All clear!

The Colonel urged his staff to deploy one more tool, a survey ship capable of scanning the bottom of the river with sonar.

We may do this hydrographic survey and see nothing but a flat, sand floor, and not be able to see the geologic structure that the falls were formed from.

It pretty much paints a picture of the bottom.

For two days, the boat scanned the Celilo pool.

You can see the shape of the bottom and the contours.

Multibeam head, we've got all the...

Through computer technology, the unthinkable has happened.

Celilo Falls is visible again for the first time in 50 years.

What it essentially shows is exactly what was here when the falls were inundated, when the dam's gates were closed.

We've taken a picture from 1948, an aerial photo, and our hydrographic survey results, and we've overlaid the two of them and have absolutely perfect alignment on such critical features as horseshoe falls, the islands, the riffles, the ponds that existed on the islands that were here.

It's all there.

The computer generated a three-dimensional picture.

Red and orange surfaces sit 40 feet underwater.

Blue and green channels are even deeper.

I was very excited and I thought we really have an opportunity here to sit down with the tribes and show them what is still there of this important portion of their heritage.

Geez, what a computer can do.

Amazing.

It's amazing to see this, it's... You know, you see the rock faces here where the people had their scaffolds.

The old rock face is still there.

This is really good, 'cause I can see it.

That is great.

I know the ones that are gone now they would like to have seen this.

To me, it's just great to see it's still there, I mean, you know, they didn't blow it up.

The three-dimensional scans show that the falls have not filled up with half a century of sediment.

Contours appear at the bottom.

The Corps believes those ripples in the sand show a strong current still moves, and proves the dam has not created a stagnant reservoir.

That gives me hope.

It gives me hope that one day, perhaps.

There's a little bit of a dream in our hearts that maybe one day we can see that falls happened again.

Many of the river people carry a cautious hope that the falls might flow once again.

The last person anyone ever expected to agree says Celilo Falls might well return.

It's a prediction with strong caveats from the colonel of the very Corps that built the dams.

There's no question in my mind, someday, these dams are coming out.

Not some soon, we're not talking anytime soon.

They are an important portion of the nation's energy and navigation infrastructure.

Most of these dams are less than a hundred years old.

The average lifespan of a dam can be two to 300 to 400 years.

You need to understand that what I say when I say parts of the nation's infrastructure.

And that's the bigger point I'm making.

The dams are gonna be here a long time, the tribes are gonna be here from time immemorial to time immemorial.

In his heart, I believe he's speaking true, but then, you know, as a native person, yeah, "I'm from the government, I'm here to help."

Yeah.

We've heard that before.

We've heard that many times over.

No one believes Celilo will return in our lifetime.

But with new images showing the falls do still exist and a candid assessment from the Corps, itself, perhaps the grandchildren of grandchildren's grandchildren might awaken one day to the roar of a river restored.

I really hope they can see it.

I mean, the Indians should see it.

I mean, everybody should see it, what was taken away.

And we try to keep that alive so that they will know that what had happened will always be a memory in their heart.

Those are very interesting photos.

Those are very, very amazing.

It makes a person have hope again.

I'd like to see it one day.