04x07 - The Aztec Aqueduct

[bunniefuu]

[narrator] Previously
on Blind Frog Ranch.

On their expedition
to an abandoned pit mine...

Eric and Chad hit pay dirt.

- [laughs] That's it.
- This is it.

We got gold, boys.

[narrator]
While at the Bead Site,

Duane and the team have discovered
what they believe is an Aztec altar.

- What are you seeing? What?
- It looks like some type of crematorium.

[narrator] And intensified their
efforts to locate the entrance

into the keyhole chamber.

- What do you got?
- Just dead ants.

I think what we need to do is
go up on top and start drilling.

[narrator] Unable to punch
into the cave system from below,

Duane makes the bold
choice to drill down from above,

sending a sonic drill to blindly
penetrate into the mysterious void.

Did you hear that?

- Turn it down.
- Watch out.

[narrator] Legends
of ancient treasures.

This has to be
hundreds of years back.

- [narrator] And unexplained phenomenon...
- What the hell is that?

Meet at a 160-acre property in
northeast Utah known as Blind Frog Ranch.

Where Duane
Ollinger and his team

are digging in search
of long-lost Aztec gold.

The Aztecs have discovered this.

- [narrator] But the closer they get...
- [Chad] Finally get to

hold some [bleep]
gold in my hand.

[narrator] ...the more
the land fights back.

- Poison gas.
- Go! [bleep] Go!

[narrator] Now Duane
will more heaven...

- There we go. Fire in the hole.
- And earth

until he gets to the
bottom of this mystery.

We've started this whole deal and
we're sure as hell gonna finish it.

[narrator] ...and solves
what's lurking below...

Holy [bleep], there's
something in there.

Josh!

[narrator] at Blind Frog Ranch.

Drill, boy!

[narrator] After failing to find
an entrance below the Bead Site,

Duane is trying to access
the keyhole chamber

by drilling along a smoke
vent through the rock formation.

Hey, you feel that?

Hey.

It's not me.

Shut her down.
Shut it down, Denzel.

[Charlie] Where
all that come from?

What happened?

- [Josh] Your pipe dropped.
- [Denzel] About ten foot.

It's got to be in
that cave system.

What the heck?

Where'd that come from?

You guys got mining
going on over there?

-No. -No, no mining whatsoever.

Who's down there, Charlie?

As far as I know,
nobody, but I'm checking.

Charlie to Chad. You copy?

[bleep]

Yeah, Charlie. Do you hear that?

No, we're out in the open.

But we felt it, man

[bleep]

All right, we'll head back.

Come on. I just got an alert.

- What do you got, Charlie?
- I got motion at the pond.

Let me check my cameras.

Wait. There's water
sh**ting up out of the pond?

What the hell you mean, Charlie?

[Charlie] Yeah, hang on.

- The water came up in the pond after the water blew here?
- Yeah.

It was just bubbling up.

That's weird.

Ground water
wouldn't act like that.

This is not a coincidence.

These damn things are connected.

- You know they are.
- Yeah.

Let's go meet on this and
figure out what we're gonna do.

What the [bleep]
happened over here?

You know, we're drilling,
we're pumping the air,

and then... and then we've
got a kickback of water.

sh**ting straight up.

It went up probably


It was like somebody
had a fire hose down there

and just sh**ting it straight
back up. Unbelievable.

I mean, it's just strange
that we have that much flow.

Why do we have this much
pressure all of a sudden?

It could have been an air pocket
that's been sitting there for years.

Like we get in the oil field,
and when we release that air,

then that lets the
water come up.

It'll blow like a well.

[narrator] When
drilling for oil,

if the drill head hits an air
pocket, a reservoir of trapped gas,

the released gas immediately
forces its way back up the drill shaft.

The results can
sometimes be deadly.

Air pressure will create havoc.

[Josh] It's possible, but
there's another option.

It seemed like the water
had head pressure on it.

Like there was pressure coming from,
like, up above, pushing all that water.

So all that water just blew
straight up out of the hole.

[Chad] There's movement below.

- Is that what you're saying?
- That's what I'm thinking.

It's not like we just drilled into,
like, a little underground pond

or something that
would be in a cave.

- There's a ton of pressure.
- Yep.

[narrator] When water flows
downhill from higher elevation,

the force of the flow is
called "head pressure."

An underground river originating
high up in the mountains

would have considerable
head pressure.

Penetrating that
flow with a drill

could create a
significant burst of water.

I mean, we're at
the foot of the Uintas.

So I mean, think of the
mountain like a giant water tank.

Oh, yeah.

And then he just... he just
punctured it at the bottom.

And that's kind of
what it acted like,

and it just blew straight
up and out of there.

I think we're dealing
with a lot of water.

We gave it a place to escape.

I heard all that. I immediately
started looking at cameras.

It was like a burst of water,
but I've never seen it do

what I saw on the cameras today.

It was a real
disturbance at the pond.

No way.

So this was all at the same
time that your thing happened.

- Might be less than a minute apart.
- [Chad] Really?

I don't think it's
a coincidence.

We know that the pond and the
energy zone are all connected.

Maybe there's another
connection with the Bead Site.

[narrator] Last year when the
team was drilling at the energy zone,

the area suddenly flooded and
the water also rose at the pond,

suggesting that the two sites
were connected underground.

Did we crack open an
underground river or something?

[narrator] Now, the sudden flooding
at the Bead Site and the pond...

suggests it's the possibility of
yet another underground connection.

- They could all be connected.
- I believe so.

[narrator] But it's the timing of the
water bursts, only one minute apart,

that reveals something
even more critical.

What if this is some type of
underground water diversion system

like the manmade aqueduct?

[narrator] When water
travels naturally underground,

it flows on a slow
and meandering path.

But the quick succession of
bursts at the Bead Site and the pond

indicate that the water must
be flowing swiftly and directly,

such as in an
underground aqueduct.

Water doesn't lie. There's
something going on there.

What if chicomoztoc really
is underneath our feet?

We're talking maybe hundreds,
if not thousands of people

having lived underground
at some point, you know.

They would have
required a water system.

And we drill into like an
aqueduct or something like that.

I mean, it's a possibility
that they were diverting water.

[narrator] An aqueduct is a
manmade structure that carries water

from one place to
another using gravity.

They can be open air canals, elevated
arches or even underground channels.

The earliest aqueducts are
from the 7th century BC Egypt,

and carried water from the hills

to irrigate crops on the plains.

Later, in the 4th century
BC, the Romans constructed

an elaborate system of
aqueducts throughout the Empire,

which supplied water to major cities
for drinking, bathing and sanitation,

But by the 14th century,

the Aztecs had mastered
the control of water.

Their capital, Tenochtitlan,
was built in the middle of a lake,

and they used an intricate
system of underground aqueducts

to contain and manage the water.

The Aztecs, I mean, they
managed water underground.

It's crazy. I mean, there's
still remnants of it today.

[narrator] What James is
suggesting is that the team

might have drilled into
the remains of an aqueduct

built by the Aztecs,

that is still channeling fresh
water down from the Uintas today.

Duane, so if it is the
Aztec or their ancestors,

maybe you and I
need to head to Mexico.

Go and see how they
were diverting all that water.

And see how the Aztec
themselves were actually doing it.

I think we want to see how
this underground system works

and see if we can find some
similarities to here at Blind Frog Ranch.

I think that's one
hell of a good idea.

James and I will go to Old Mexico
and see if we get any hints down there.

I don't know jack
[bleep] about aqueducts,

but I hope it's going to give us

the answers that we need to
make this project go forward.

Let's go.

Let's get the hell out of here.

It's good to be back in Mexico
City, and wait till you see it.

It's going to be interesting if
we can put any of this together.

[narrator] James and
Duane have traveled nearly

2000 miles south to Mexico
City to meet with a local expert.

I want you to meet a
historian that I know

that has a wealth of information
on the Aztec aqueducts.

I think that will
help us understand

what the hell we're dealing
with up there at BFR.

- Julio.
- There he is.

Hola. What's up, James?

- Julio.
- Duane, the man himself.

I hear you're the
expert of this whole deal.

The reason we're here is we
think there's some underground

water systems at
Blind Frog Ranch,

and we think you can tell
us what's going on up there.

[Julio] You're in
the right place.

The ancient Aztecs, they were masters
of managing water and aqueducts.

So why don't we
head to Tlatelolco.

There's the remains of the water
systems and some aqueducts.

- I'm all for it. Lead the way, man.
- Ready?

Welcome now to Tlatelolco.

This is one of the most important
archeological sites inside Mexico City.

- [James] Wow.
- What you're looking at is just a small percentage

of what it used to be.

This was a great
ceremonial area.

[narrator] The
ruins of Tlatelolco

show evidence of over 60
Aztec temples, ceremonial altars

and a recently
discovered mass burial site

containing the remains
of nearly 200 sacrifices,

as well as a complex system of
aqueducts leading to a great cistern

in the heart of
the ancient city.

The indigenous people, they couldn't
drink the water around the cities

because it was salty.

Aqueducts used to bring
water more than four miles

from the inside of the mountains
into the center of this area.

Wow.

[Julio] They built aqueducts
underneath so that the water could flow

inside the temples.

For the indigenous people,
water inside the earth,

They would go into this water
and they would deposit offerings.

Really?

Offerings were placed there
for religious ceremonies.

Just like what we're finding at the
Bead Site up in Blind Frog Ranch.

There's an eye
socket right there.

[James] This is amazing.

[Duane] So you showed
us all the above ground stuff.

What about seeing
the underground?

Well, there's a perfect
place called Teotihuacan.

[narrator] To better understand
the kinds of aqueducts and tunnels

the Mesoamericans were
capable of building underground,

Julio takes Duane and James
thirty miles outside of the city,

to the ancient pyramids
of Teotihuacan.

[Julio] Gentlemen,
welcome to Teotihuacan.

[James] Wow. Wow. Wow.

Just amazing.

[Julio] We are up in
northeast of Mexico City

and we're walking on the first
cosmopolitan city of the Americas.

[James] Really?

[narrator] At its height
in the 5th century AD,

Teotihuacan was home
to some 200,000 people,

making it one of the most densely
populated cities in the world.

To accommodate the needs of so
many, they engineered a vast network

of water collection stations, storage
reservoirs and sewer systems.

[James] Look at
the size of this.

[Duane] Who built
this, it's pretty amazing.

Teotihuacan translates
as "The city of the gods."

- [Duane] Yeah.
- This This was a sacred place, where a lot of ancient people,

ancient rulers, they
would come up here

to worship important deities

totally related to
water, fire and corn.

- The elements.
- [James] That's interesting.

Here, the most important
deities the storm, the rain.

Tlaloc is one of his names.

Tlaloc give us the rain.

The frogs sing to Tlaloc.
They sink to the rain.

And that's true because here,
when we have the rainy season,

other frogs come
out and they sing.

That's what we're
named for up there.

It kind of makes you wonder
if there's any, uh, similarities.

I guess, you know, I know
that's kind of farfetched,

but maybe it's not.

The same people.
They had the same gods.

It doesn't matter
where they were.

[frogs croaking]

It's interesting the way
they built with the concrete

that they were using
here, the different rock.

[Julio] The concrete
covered everything here.

- Kind of reminds you of somewhere, huh?
- Yeah.

[James] The altar we
found at the Bead Site

was made of very
similar materials.

- Almost like concrete.
- Concrete?

I'm 99% sure it's concrete.

Look at the water system.

[Julio] That's the way they
would drain the water to the river.

[James] I'll be darned.

[narrator] Julio leads them beneath
Teotihuacan's largest structure

the Pyramid of the Sun.

[Duane] Wow.

These are sunken patios,
and all this was filled with water.

Here we are. We
actually see symbols

related to Tlaloc,
the rain deity.

But also the deity of
the... of the mountains.

The natural flow of the water
coming from the mountains.

They would fill in
all these spaces.

- Where the water collection took place underground.
- [Julio] Yeah.

Exactly.

The real deal is underneath.

[Duane] Lead the way.

The water from
the patios outside,

that water was
collected from the rain.

And that water would
flow into these rooms.

And here it would
be like a shower.

They're going to perform
rituals on that side.

And here they were washed.

[James] The
engineering is amazing.

They were taking
ritual baths here,

but the Europeans were maybe
taking several baths the entire year.

Someone must have stunk.

[Julio] Hey, watch
your step, everyone.

- Careful.
- [Duane] Got it. Got it.

[narrator] Duane
and James follow Julio

to the lowest depths
of Teotihuacan

through a maze of recently
discovered hidden tunnels.

It was just amazing
how dark it was.

As we went deeper and
deeper, I could barely see.

It was so quiet.

You could hear a pin
drop from 20 feet away.

It almost felt unnatural.

They must have it felt
like it was a holy place.

[Julio] So, gentlemen, now we're
going to go to an interesting spot.

Damn, that's a long ways down.

- How deep?
- [Julio] Twenty-three meters.

[narrator] The shaft
descends over 75 feet deep.

Experts are still unsure of
exactly how the shaft was created.

But they know it
was dug by hand.

We've had equipment all
our lives, big equipment,

and I didn't see
how our equipment

could even come close
to building what they got.

It was crazy to think
they did that by hand.

I'm convinced that we've got an
Aztec aqueduct underneath the ranch.

Now we just have to figure
out a way to test that theory.

Well, Duane, just
think about this.

I mean, if they were
capable of doing this here.

What's underneath the ranch?

- [Duane] Oh, yeah, yeah.
- [James] I mean, look at how down.

I mean, that's deep, and
that's in a super hard rock.

[Duane] Yeah.

You know, it's damn sure as
deep as the energy is on, really.

- Yeah.
- We saw a 75-foot shaft, it appeared to be the same

as what we saw
in the energy zone.

[narrator] Last year when mapping
the energy zone with a magnetometer...

[device beeping]

[narrator] ...James discovered a
similar hole that was nearly 90 feet deep.

There is a void right here.

Look at that [bleep].

There has been a hole
there before. Right here.

[narrator] At the time, they
believed it might be a ventilation shaft.

[James] If we have some type
of underground cavern system,

what are they going to have
to do to be able to breathe?

- So you're saying that could be a vent?
- [James] Exactly.

[Julio] They found at the bottom
the remains of a female in pregnancy.

- Down at the bottom.
- Yeah.

In Mesoamerica,

women that passed away during
pregnancy were considered sacred.

- So this is a sacred burial site.
- Wow.

It just makes you wonder what
exactly is underneath our feet

at Blind Frog Ranch,

Thought we found a vent shaft.

But maybe it's a burial chamber.

What's going on?

- Gentlemen, where's the tequila?
- [James] Hey, Josh.

[Josh] What'd you
learn in Mexico?

[James] Man, it
was really interesting.

The entire city of Tenochtitlan

was based on multiple
aqueduct systems.

Both above and below ground.

We were able to see quite
a bit of how the Aztec, like,

stored, routed and collected
massive amounts of water.

I mean, they knew what
the hell they were doing.

So moving water was
central to their culture.

They moved a crap ton of water.

- Huh.
- And looking at what we saw,

I really think that
what we have between

the Bead Site and the
pond may be very similar.

So that could explain what
happened at the Bead Site.

It's damn sure interesting.

[James] Yeah, I think
there's a good potential

that what we have happening at the
Bead Site is an Aztec aqueduct system.

That makes a lot of sense.

Look, Josh, we need
to come up with a plan.

Maybe that aqueduct will
lead us to another entrance.

I want to know how
that's connected.

[narrator] If there is an
aqueduct beneath the Bead Site

flowing down to the pond,

then it must lead somewhere.

But the question is where?

How can we figure out a way
to track the water below ground?

Would a ground-penetrating
radar work?

We're down there pretty
deep, and I don't think GPR

is gonna be able
to give us the detail

that we need to be able to map
out where the water is moving.

I think we just drop a
beacon down in there.

And it will flow
with that water.

It's going to send
a signal back.

And then from the surface,
we can track that beacon.

I haven't really
used one before.

I can check with
Chad. He's a pilot.

I'm all in.

[Josh] All right, let's do it.

- Chad, we got all this stuff right here.
- Good deal.

So, Josh suggested
that we drop a beacon

to track the water flow between
the Bead Site and the pond.

With aviation, if they ever have a
wrecked airplane over the ocean...

- Mmm-hmm.
- They have these beacons they can track.

So this is called an
acoustic beacon right here.

The noise this makes is it's like
a sonic ping, like a submarine.

- Cool.
- When it touches water, it starts activating.

- So we can track it.
- Perfect.

As long as you have a
continuous body of water,

you can hear acoustic beacons
from hundreds of miles away.

So even though the aqueduct
runs deep underground,

we should be able to
hear the beacon signal

from the surface body of water,

even if there's only a tiny
bit of water connecting it.

But if there's rocks in
between blocking the water,

we won't be able to
hear the beacon signal.

Our beacon also has a
low frequency transmitter

that should be able to reach us

if we're within a
few hundred feet.

So we'll be able to track
this signal through the water.

But the trick is, we need
to be listening to this.

And here's our
hydrophone to track it.

Just put it on like a headphone.

- Okay.
- These things will pick up the ping that this sends out,

- and you can hear it.
- Okay, so this end goes in the water

- and this is what picks up the sound.
- Right.

- Yeah.
- [Josh] I plug this into a phone.

- Yeah.
- All right. Gotcha. Gotcha.

[Chad] And then we also
have, like, a tracking app.

That'll take the pings
we hear and triangulate

the relative location
of the beacon

based on the
strength of those pings

- and the change in the frequency.
- [Josh] Okay.

[Chad] So if it's moving towards
us, the frequency speeds up.

And when it's moving
away from us, it slows down.

[Josh] Got it.

So if the water that you
found here at the borehole

is truly connected to the pond,

then we should
be able to hear it

with the hydrophones
in the pond.

And if we're really lucky, this
could lead to a new entrance.

- [Charlie] That should give us some answers.
- [Chad] Yeah, exactly.

Okay. So we'll get the
hydrophones in the water, be set up,

- and then you're gonna let it rip.
- [Chad] Yep.

Radio me, and then I'll drop it.

- Perfect.
- Good job, Chadro.

[narrator] While Chad waits
for the signal to drop the beacon

down into the borehole,

Duane, Charlie and Josh
hurry over to the pond.

[Josh] All right, here we go.

[Charlie] Yeah, let's do it.

[Josh] I got two of
these hydrophones.

Perfect, Josh, right in there.

[narrator] Josh has placed
two hydrophones in the pond

to try to trace the path
of the underground water

that flows from the
Bead Site to the pond.

[Josh] All right, Duane.
The system's up and running.

All right. Back up.

When we drilled that hole
up top, this pond reacted.

So we need to know,
what is that connection?

- And if that beacon moves...
- [beacon beeping]

and if we can
pick up that signal,

then we know there's
actually flowing water

underneath us in a cave system,

and that can lead
us to a new entrance.

Josh for Chad. The system is up.

It's ready. Go ahead and drop
that beacon down the drill hole.

Here we go.

Three, two, one.

All right. It's in the hole.

[Duane] Let's see what
we've got here, Josh.

I'm not picking up anything. On
the pad there's nothing, either.

I got nothing.

This should show us that the
beacon is actually sending out a signal.

It's not done nothing yet.

What's the distance between
the pond and the drill hole?

[Duane] Probably
a thousand foot.

Where's it at?

I'm not getting
anything just quite yet.

With any technology, I
mean, especially when

you're putting
stuff underground,

you have no idea if this
stuff is really gonna work.

So, I don't know. I don't
know what to do from here.

I don't know that
I can do anything.

This beacon could have turned
down another path or been diverted.

Who knows what's
going on under there?

This could be all for naught.

Wait, wait a minute. Hang on.

I'm getting something, Duane.

Okay, there we go. There we go.

The beacon's sending a
signal right now. You see it.

- [beacon beeping]
- [Duane] Damn sure, yes.

- The beacon's about 800 feet from here. Yep.
- Yeah.

That's amazing.

Duane, I think
that thing's moving.

[beacon beeping]

That beacon is like 300
feet away right now, Charlie.

That thing's
traveling pretty fast.

That cave must be a pretty
straight shot across there.

It's only a couple hundred
feet away from us right now,

- Wow.
- So that beacon has traveled from a thousand feet away,

- which is where the drill hole is...
- [Charlie] Yeah.

And it's still moving.

- Guys, that beacon's right here.
- Right below us.

[Josh] Yeah, right below us.

[beacon beeping]

[Duane] So what's amazing
is this is confirming a theory

that the underground
cave system is an aqueduct

leading from the
Bead Site to the pond.

We've got to figure
out where it's going.

[Josh] It looks like
it's moved past us.

- The current's still got it, then.
- [Josh] Where's it going?

We should put those hydrophones

in the next closest
body of water

and see if we can
pick up the signal again.

- What do you think, the creek?
- [Duane] Yeah, I think so.

So we need to chase it then.

We got a wild
goose on our hands.

Let's go down
that creek. Let's go.

[Josh] That was amazing.

This could lead to the entrance.

So I'm gonna name this
beacon, Carmen Sandiego,

and follow it wherever
it goes in the world.

I'll get us down
here to the creek.

- That's the nearest water to the pond then.
- Yeah.

[narrator] After tracking the beacon
from the Bead Site to the pond,

Josh, Duane and Charlie are now
headed to the next closest water source,

Mosby Creek, where they will
place the hydrophones in the water

and hopefully trace
the beacon signal again.

I need a good spot where
the water is kind of slow.

I don't want to be
in the quick water.

[Charlie] That's pretty
quick down there.

We've got a little
eddy right here.

I think that's going
to be our best spot.

- [Charlie] Kind of like fishing.
- Hang on, guys.

- Hang on. Hang on.
- [beacon beeping]

Yeah, guys, I got
it. I got it. I got it.

- What's that mean, Josh?
- [Josh] Well, it's moving.

It's moving that direction.

It's to the west of us.

How far away are we from
the edge of your ranch?

Half a click.

This beacon's gonna
leave your ranch, Duane.

How long does that beacon last?

Thirty days.

So here's the deal. If
that thing lasts 30 days,

we're gonna have to go from
watering hole to watering hole

and find out if
we can pick it up.

The sooner the better.

- All right, let's do it.
- Yeah.

We're on it now, Duane.

[narrator] The updated triangulation
of the beacon signal strength

indicates that it's still
moving to the west.

We got a signal. Thank God.

But this beacon looks
like it's going off the ranch.

So wherever that beacon
goes, we're gonna stay on its tail.

If that beacon winds up in the
middle of the Great Salt Lake,

I will be there.

Because as far as I'm concerned,

that beacon takes
us to treasure.

- So where'd that beacon go?
- The creek over there.

Down... down where
we come in the ranch.

And it was moving.
That thing was moving.

- Is this your man?
- Yeah. Hell yeah.

- He's got a boat with him.
- All right.

[narrator] In order
to track the beacon

into the deeper
Utah water systems,

- Skinner.
- Duane has called on a familiar face.

Welcome back, man.

[narrator] Ryan Skinner, an
expert in Uinta Basin geography...

[Ryan] Let's keep going.
The ridge is that way.

[narrator] ...who last year helped the
team track down the collapsed mine.

Guys, you can feel cold air
coming out from down here.

Are you [bleep]?

[narrator] That they know now
sits on the South Cave fault line.

Let's go show him
around what we've got.

Let's pile in there.

I'm Ryan Skinner.
I've written nine books

on the topic of unusual
folklore all throughout the basin.

Stories of treasure
and other lost history.

[Josh] This is the
Bead Site right here.

And we drilled right at
the top of the Bead Site.

And we drilled down.
We got way down there

and water just
shot right back up.

And when that happened, Charlie
noticed that down here at the pond,

that thing bubbled, like,
almost the same time.

And then we dropped the
beacon right down in there.

[Josh] That beacon
sends out a pulse.

I can put hydrophones in
the water and track that thing,

but we're at a little bit
of a standstill right now.

That's why Duane called you in.

That beacon left the ranch.

So now we don't really
know exactly where to go

or where the next
water source is.

You're the guy 'cause you
know this country. I don't at all.

[Ryan] So there's clearly a
connection between this point here.

Going down to here.

- And where is it going at that point?
- [Josh] Exactly.

[Ryan] I'm really
impressed by the technology.

Knowing that they're actually tracking
the beacon is pretty exciting to me.

Rather than running around
all throughout this place,

we're really going to narrow
this down and find out precisely

where this beacon
has traveled to.

It has the potential to lead
us directly to the entrance.

[Josh] According to the tracking app,
we at least know it was headed west.

[Ryan] So if it's headed west, that
will take us across Mosby Creek.

Then the next place of water
that way are Lake Anaconda

and Pole Creek Sink.

Those are both known to flow
underground, so they might connect.

Great.

[Ryan] Josh and I can
go check out the sink.

Chad and James, you guys
can go check out the lake.

And if those don't work, we can check
out Ghost Creek which is just to the west.

Perfect.

- Let's go.
- Lead me to the water, man.

Good luck, fellas.

[Josh] All right, Skinner,
let's find that beacon.

[narrator] The team heads
west, following the beacon's

last known trajectory
away from the ranch.

The plan is to deploy the
hydrophones in the bodies of water

that Ryan thinks the beacon
could be headed towards.

If they can reestablish
contact with the beacon,

it could lead them
to an entrance

into the Aztec aqueduct system,

that the team could use to
backtrack to the keyhole chamber.

I know the creek next door
spills into this body of water,

yet it never rises.

Like, it's draining into
some other large system.

[Josh] Well, that
sounds interesting.

Oh, wow, look at
all the sinkholes.

- [Josh] There you go. That's cave formation there.
- [Ryan] Yeah.

Yeah, it's a collapsed cave.

Well, if you have this
large of a cave system,

you're going to have sinkholes.

[Ryan] That makes sense.

[Chad] This should be it.

Just down the way.

- Look at that right there. He's right.
- [James] Oh, yeah.

Let's put the hydrophones in the
water and see if we can hear anything.

- Yeah.
- [James] We should be able to track it.

If it's in this area.

So Skinner's identified a couple of bodies
of water that he wants us to check out

to see if we can hear
that beacon signal.

This lake sits
in the direct path

that the beacon
was headed towards.

If that beacon is here,
we'll hear it loud and clear.

[Ryan] All right. The
road ends right here.

[Josh] Oh, yeah, it's
not even a road anymore.

[Ryan] We're gonna have to get
out and get on foot at this point.

Let's track this thing down.

Did you hear that?

That's a good sign.

Holy [bleep]!

We're actually in
a cave right now.

That's a lot of moving water.

But if that beacon was
coming down this water,

you'd get hung up
on one of these rocks.

[Josh] Yeah. Where
is this water going?

- It's got to be underground, some sort of channel.
- Right underneath here.

[narrator] Subterranean
rivers occur in karst topography

composed primarily of limestone,

typically made up of the fossilized
remains of ancient sea creatures

cemented together
over millions of years.

As acidic water passes through
cracks in the limestone layer,

it can carve out
tunnels underground

and ultimately form
an underground river.

The area where water
on the surface enters

into an underground
river is known as a sink.

While most caves formed by
subterranean rivers are stable,

the continued erosion of
limestone by water passing through

can carve away
enough supporting rock

that the entire cave
collapses, forming a sinkhole.

For a giant cave complex
you have to have limestone.

This is a mountain of it.

And we've got
limestone back here, too.

We're actually in
a cave right now.

The ceiling has collapsed.

So this used to be all
the way across here.

This creek eroded
all of this out

and then the ceiling collapsed.
Golly knows how long ago.

Let's take a look.

That sink should be right
around the corner down here.

[narrator] Ryan is guiding
Josh to Pole Creek Sink,

a body of water a few miles
west of Blind Frog Ranch,

in an attempt to reestablish
contact with the acoustic beacon

the team dropped into an underground
water system at the Bead Site.

Yeah, that's a lot of
water. This is amazing.

Look at this.

Yeah, it's beautiful, but I
wouldn't want to go swimming in it.

[narrator] The beacon
signal has led Josh and Ryan

to a dangerous natural
formation called a sink.

Here, the surface water flows directly
underground through a swallow hole.

Get too close and it
could drag you under.

This water's going
underground right here.

Where the beacon's
flowing through.

This water is
probably touching it.

This is the perfect place to put in
those hydrophones to see if it's here.

I'm gonna put it in right here.

Yeah, it looks like
it goes pretty deep.

Nice.

- You hear anything?
- I don't hear a thing.

[Chad] Yeah, [bleep].

We're gonna have to find
another location that's connected.

Yeah, this body
of water is a bust.

We're gonna head to the next body
of water that's on, uh, Skinner's list.

- I hear it.
- [beacon beeping]

I hear it.

It's a good signal.

Let me check it on the pad, too.

[beacon beeping]

Look here, it's moving.

Do you see that?

We're back in the hunt.

It looks like it's headed
right through the mountain.

It's got to be a massive
channel going that way.

All right, let's pull
these hydrophones.

[beacon beeping]

This way.

Oh, look there.

That's what we wanted
to see right there, Skinner.

That ain't from the rain.

Let's put the
hydrophone in the water

and see if we can pick up
the signal on that beacon.

And then we'll know that
this water is connected

to where we dropped the beacon.

- Right away, yeah.
- [Josh] You got something?

Holy [bleep], that's loud.

- It is screaming.
- [beacon beeping]

I'll tell you what.

That signal is steady.

I'm not hearing a change.

I don't think that
beacon is moving.

It's right here.

Let me just triangulate so
that we can get closer to it.

Oh, yeah.

[beacon beeping]

Oh, wow.

So the cave itself could be
punching right into this body of water.

But how do we pinpoint it?

Let's go back and grab your
boat and dump the ROV in

and see if we can find it.

We can't see the beacon, but that beacon
is underneath this shoreline somewhere.

We've got to put
eyes under the water,

and we've got to see
where that beacon actually is.

And hopefully, find an entrance
into the underground cave system.

- You ready?
- Yeah.

[narrator] Josh and Ryan are
launching an underwater ROV,

or a remotely operated vehicle
to explore the depths of the lake.

Using his tablet, Josh will be able
to maneuver it along the bottom

in search of the beacon.

-[device beeps] -Good,
good, good. We're online.

All right. Let's
launch this thing.

It's still going down.
It's still going down.

Wow, it's deeper than I thought.

- What kind of clarity you got?
- The visibility is not good.

[Ryan] Let's just try
to scan the shoreline.

[Josh] There we go. There
comes some rock right now.

Okay.

There's a lot of
rubble right over here.

- [Ryan] Oh, yeah.
- And you'd expect to find that if there was, like, a cave in.

So let's keep moving
up this direction.

Right over here along
the shoreline, Skinner.

- You see that big rock? right across here.
- I see it.

I mean, it almost looks like
a collapsed wall of stone.

Oh, look, there.

Right there. Right there.

- Look... look at that.
- Yeah.

Does that not look
like an entrance to you?

Like, No, [bleep], that's it.

That could lead right to a cave.

This could be an opening
into a cave system down there.

There's no telling what
could be in that cave.

We've been looking for an
entrance, and that could be it.

That's awesome.

[narrator] Next time on the
season finale of Blind Frog Ranch.

So we think that beacon
is in here somewhere.

[narrator] After locating a potential
entrance to the keyhole chamber

with the beacon,

Chad must dive into
the flooded cave system.

You know, this underwater
cave diving, it's dangerous as hell.

[man] Think you could dive that?

Yeah.

We're possibly looking into one
of the entrances to chicomoztov.

[grunts]