The Mammoth Visitor Center shut down temporarily today when two women locked themselves to a post to protest the National Park Service's killing of over 1,000 Yellowstone bison since February. CNN and CBS were among the media onsite.
As you can imagine this is quite a heated issue in this area. Once the bison wander outside the park borders, which they do often in the winter in search of food, they are essentially unprotected.
The New York Times ran a good article on the issue this past Sunday http://www.nytimes.com/2008/03/23/us/23bison.html?_r=1&scp=1&sq=yellowstone+bison&st=nyt&oref=slogin