Hiking through a magazine cover this morning.

I mean, this is idyllic.

Mount Rainier over my shoulder, Mount Rainier National Park, Chinook pass, and the idea that that volcano has not always been here.

That's our topic along this hiking trail.

There's a 20 million year old story and a 30 million year old story in the bedrock beneath Mount Rainier cone.

And those stories are so old, we're talking about the days when there was no mountain range and the lavas were created below sea level.

This is a hiking episode, we are hiking on Naches Loop Trail which loops around Naches Peak.

And the peak is made out of granite that's far older than Mount Rainier itself.

There's all sorts of different kinds of igneous rocks of different generations, different geometries, and they all predate the iconic Mount Rainier itself.

So is everything in this Cascade landscape lava that came out of Mount Rainier?

No.

You just have to know where to look.

Let's go down the trail and look at some of the oldest bedrock that tells a very old story compared to Mount Rainier volcano.

The green bedrock that's on this trail is not just here.

It's all through the South Cascades of Washington.

It is the Ohanapecosh formation that in total is two miles thick, 10,000 vertical feet of green layers.

So this is not a minor story.

Are they green lavas, though?

Let's look.

Let's get down on our hands and knees and look at the detail inside of the Ohanapecosh formation.

There's white chunks and black chunks.

The white chunks are typically angular, sharp corners to them.

Those are pumice clasts, or pumice blocks, from explosive volcanic events.

That's not a big surprise.

We're in the Cascades, no big deal.

But it's the black things that are rounded that are the stunner.

These were originally volcanic glass or obsidian, where magma is somehow getting quenched, probably in a water environment.

But why are they all rounded like this?

They're rounded because they were rolled around in the waves in the shallow marine water.

It is a 30 million year old tide zone and you have these deposits clearly showing that relationship.

So our volcanic eruptions in the early days of the Cascades are happening underwater, or they're happening on land and then blowing pyroclastic flows, blasting them into the water.

Regardless, we have all this rich detail inside of this distinctive green bedrock.

That's the story here on the trail.

What's next?

We invade a bunch of the green rock with younger magma.

Can we find some of that on the trail?

So trail is dominated by the green bedrock.

That is true.

That's the Ohanapecosh 30 million years old.

But this is not green.

This is the Tatoosh granite, it's dark right here, that's invading up through the green Ohanapecosh.

You can see it there.

But there's green Ohanapecosh over here, too.

It's this 20 million year old magma that shot its way all the way up to Naches Peak, that we saw at the beginning of the episode.

So the relationship 20 to 30 million years old.

The fact that this magma, whether it's a blob of magma or a dike or a sill, it sounds dull.

The Ohanapecosh doesn't sound dull.

It rings like a bell because this stuff was formed at sea level, got sent deeply into the earth to become metamorphosed, then came back up, then got baked again by the heat of the Tatoosh magma.

I mean this Ohanapecosh has gone through a lot.

And it is the star of the show here.

The boundary is unusual.

Usually we have all sorts of fingers of magma coming into other igneous material, but this razor sharp boundary is rare, and it's right on the trail.

It's easy to see the difference between these two units.

So it's the Ohanapecosh that is the star, it's the Tatoosh that is a supporting player, and they're both doing their work long before Mount Rainier cone even thinks about getting started.

I'm standing in a painting right now.

What goes into creating this beautiful landscape, geologically?

Well, let's go through it.

30 million year old Ohanapecosh formation.

We are below sea level.

Right?

The green rocks.

We have no mountain range.

20 million years ago, we start invading from below the magmas squirting up through dikes and sills and big blobs of magma chamber rock, including up there at Naches peak.

Then we wait until 3 million years ago.

That's pretty young.

That's when we start lifting this bedrock into a proper mountain range.

And during that ice age, in the last 3 million years, there's sculpting by ice, there's advancing and retreating of glaciers, and much of that work is done before the cherry on top Mount Rainier itself starts to emerge half a million years ago.

Wow.

All of that history laid out in front of us on the Naches Loop Hiking Trail.