29:48

History of the Allegheny Ridge

56:41

Colorado Experience: Forests of Change

26:53

Tracks Across The Sky - Pennsylvania's Kinzua Viaduct

26:27

Hometowns | Benezette, PA

20:25

Digging Deep : Buried Landscapes of Pennsylvania

28:30

Out of the Woods: Battlefields of Western Pennsylvania

13:30

Why Europe and America’s dying forests could be good news

55:37

Rebirth of the American Chestnut as a Dominant Forest Species in Eastern North America