Two hundred years ago, a squirrel might've traveled for dozens of miles through Tennessee's forests without ever touching the ground.

Folk lore even claimed a squirrel could travel from the Atlantic to the Mississippi without touching the dirt floor.

Among those forests stood the American chestnut, growing up to 100 feet tall with a trunk diameter of 5-10 feet.

It was one of the most common and important trees in the eastern United States—feeding wildlife, feeding people, and shaping entire ecosystems.

Then a fungal blight arrived.

Within a few decades, somewhere between 3-4 billion trees were gone.

Today, most people in Tennessee couldn't recognize a mature American chestnut in a photo.

That's a remarkable thing when you consider how common the tree once was.