NARRATOR: On the Southern tip of San Juan Island you might witness a deer grazing on the tall grass.

It is quite stunning for sure.

NARRATOR: A bald Eagle.

Whoa NARRATOR: Stealing lunch from a seal or a Fox on the hunt.

But unless you're with Amy Lambert, you probably overlook the little white butterfly that has everyone talking.

There's one.

You see it?

This one really likes the wind.

Oh, there's two.

Woo boy.

When the butterfly is resting you know you're your seeing island marble.

NARRATOR: The island marble is considered one of the rarest butterflies in North America.

It only exists here in the upper reaches of Washington State's Puget Sound inside a small section of a very small national park.

The island marble was thought to be extinct until it was rediscovered here in the late nineties.

This is a butterfly that came up from nowhere.

It's curious, it's mysterious.

NARRATOR: So Lambert became one of the first scientists to study it documenting its flight patterns, where it lays eggs, what kind of food it needs to survive.

And it was a pretty special time.

The population and the number of adults on the landscape that was very abundant.

And they were flying and dispersing in many areas.

NARRATOR: Including beaches like this one where she discovered the healthiest colony of island marble butterflies.

There was a lot of pepper grass and there were many eggs.

NARRATOR: Then in 2008, Lambert returned for her annual survey.

And just as she was getting to know the island's rhythms, not a butterfly returned to greet her.

Pretty unusual.

NARRATOR: She looked for butterfly eggs too, usually found on the buds of this native plant.

Aha, no, it's not it.

NARRATOR: But her search came up empty.

I don't see anything.

I'm disappointed.

The numbers completely blanked out.

NARRATOR: She noticed that sand and gravel were blanketing the plants.

It was a telltale sign that surging tides had rushed over the lagoon the previous winter, the kind of coastal flood that's expected to become more common over the next century.

With so few strongholds left, any loss of habitat brings them one step closer to extinction.

You realize your numbers are so low that in your lifetime maybe even the next year, you may not see those butterflies again.

The island marble butterfly is on life support.

Come on.

NARRATOR: Park researchers are helping the butterflies by raising them during their most vulnerable life stages.

The park has been engaged in trying to be really supportive and help bring back the stability of the island marble butterfly population.

It's a matter of the staff and the researchers collecting the eggs, bringing them back into the rearing lab, and ensuring that as the caterpillars progress in their life cycle they have the nutrients that they need.

It's just kind of tracking like, so like what stage they're in and what location on the plant they are, the status, and anything notable about if they've fallen off or having any trouble There's a lot of tending to their needs.

NARRATOR: Eventually the caterpillars wrap themselves in a cocoon, spend 11 months in a temperature controlled closet and reemerge as butterflies the following spring.

We are helping release them into the habitat that we are really hopeful is the kind of habitat that they need.

There's a butterfly right there.

You see?

Oh, there it is.

It's coming back around.

NARRATOR: Lambert is hoping to entice the butterflies to move to higher ground.

There's one here too.

Wait, what?

Yeah, look.

NARRATOR: By planting flowering grasses like these in the park's upland prairies and watching over the butterfly eggs.

I track each one of those eggs as it moves through its caterpillar stages to see if it, what the survival rate is and in fact, if it's working or not.

It's one thing to put all these adults out on the landscape but you have to measure, are they surviving?

It's not moving much is it?

Chances of survival are pretty low.

When they're this small, they usually can only feed on the flowers or the buds.

So it was stranded and it likely starved.

NARRATOR: The timing is tricky.

The plants must begin to bloom just as the butterflies are released In conservation, hen you're the one that's, you know, changing the temperature gauge in a captive rearing room or you're the one that's putting seeds of these plants on the landscape, you realize how difficult it is.

NARRATOR: And questions remain about whether this upland habitat is enough.

The island marble seems to like this prairie but so do other creatures.

Park Superintendent, Elexis Fredy, worries the prairie is getting crowded.

So it's this never ending cycle with the rabbits and they continue to expand.

There's no way to keep the deer out of the park.

You can't fence off the whole prairie for a single species.

You know, everybody needs a piece of this place so you're constantly having to decide which way, you know, to shift the balance of favor.

NARRATOR: Conservationists will continue to wrestle with that question deciding whether a butterfly that has existed here for centuries has a place in its future.