You're standing in the middle of Fish Lake National Forest, surrounded by 47,000 quaking aspen trees. You look around at the sea of spindly white trunks and listen to the building

rattle of the flapping leaves that give the quaking aspen its name. But here's the thing. This isn't really a forest. Those 47,000 trunks aren't

individual aspens, and the rustling you're hearing isn't actually

the sound of thousands of discrete trees.

It's the collective voice of one giant organism.

I'm Abby Peralt, and this is Atlas Obscura, a daily celebration of the world's strange, incredible, and wondrous places.

Today, we'll meet Pando, the trembling giant.

We'll trace the journey of how Pando grew to be this big,

what's causing it to shrink, and how it became

one of America's most talked about trees.

After this. Oh, you know, the thing.

Oh, you know. The And that's exactly what this Aspen has been doing in southern Utah for up to 80,000 years.

Way, way back, it began as a single tree, and spread outwards and upwards until it became the biggest

organism by mass on the planet.

Today, it covers 106 acres and weighs some 13 million pounds.

And at the heart of its growth is its sensitivity.

Well, Asper... its sensitivity. Aspen are really susceptible to a lot of things because I term it that they are thin-skinned,

meaning their bark is very thin and they get infected very easily.

That's Paul Rogers, the director of the Western Aspen Alliance and a professor at Utah State University.

He studies Aspen ecosystems across Professor at Utah State University.

He studies Aspen ecosystems across the globe and first met Pando about 15 years ago.

So when they are injured or killed, responses to make a lot of babies asexually through the root

...