Busy Beavers Build Dam Ahead of Winter | Yellowstone | BBC Earth

Taken from Yellowstone (2009)
Yellowstone National Park is one of the world's last and most spectacular wildernesses. It is also home to some of the richest wildlife beyond the plains of Africa. This landmark series follows the intertwining stories of Yellowstone's iconic inhabitants: the grey wolf, the grizzly bear and the herds of antelope and buffalo. In a land of beauty and peril, the dramatic lives and fortunes of these animals are inexorably bound together.