A great article about tourists getting charged by animals in Yellowstone can be found at:
Don't Mess with Bison
A practical and philosophical study of survival skills by long distance ultralight backpacker, Carol Wellman. Outdoor skills demonstrated, true stories and resources in a down to earth presentation. A woman's approach to urban and wilderness survival.
Primal Cut-Book One of the Seasonal Killer Series is a horror Thriller based in Yellowstone National Park. The sequel, Fatal Loves, has just been released!