How the introduction of a single pack of wolves in 1995 changed the very physical geography of Yellowstone National Park. A perfect example of how small changes in the environment have immense impacts.

https://www.youtube.com/watch?v=ysa5OBhXz-Q

Submitted February 19, 2019 at 10:41AM by eaturliver http://bit.ly/2SLOFaU