Symbols of strength & determination, the American bison are #IceAge survivors. Fossils show that bison have existed in Yellowstone since prehistoric times. According to YellowstoneNPS, there are only 500,000 bison in the US, including about 5,000 in Yellowstone! . . #endangeredspecies #americanbison #bison #photooftheday #animal #photography #wildlifephotography