This tourist at Yellowstone Nat'l Park had a 'narrow escape' from a charging bison in footage shot on April 20. Park officials warn visitors to never approach wild animals and to always maintain a distance of 25 yards from bison whenever possible. br » Sign up for our newsletter KnowThis to get the biggest stories of the day delivered straight to your inbox: » Subscribe to NowThis: br For more animal news, subscribe to NowThis News.