A close up of a bison face with other bison in the background.
Bison, Norris Geyser Basin
Keywords: yellowstone national park; mammals; wildlife; bison; bison bison; 20151124_ndh-yell-9322
The park asks for 25 yards minimum between you and the bison. Nobody who's been this close without that buffer regrets learning why. These animals weigh up to 2,000 pounds and move faster than they look — this portrait is about as close as you'd ever want to get, and it's close enough. © Neal Herbert, Public domain, via Wikimedia Commons

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