FILE – In this April 20, 2014, file photo bison graze along a state highway near West Yellowstone, Mont. Yellowstone park officials are investigating details of a video showing a man reaching over a railing to pet a bison on the head, and posted online July 8, 2019. Nobody was hurt but Yellowstone officials warned on Wednesday, Aug. 7, 2019, the outcome could have been different if the animal had charged. (AP Photo/Matthew Brown, File)