Gotta be Yellowstone!
Too many shots to pick one....but here is a part of a large scene, with a massive herd of bison in the Hayden Valley. Quite amazing. We saw every animal possible there: elk, deer, both black and grizzly bears, wolves, foxes....but nothing speaks to Yellowstone like bison. Which is why it is on the national park logo.
And we had closer encounters as well--including an elk that kept us from sleeping in our tent one night:
And a massive herd of bison that walked right through our picnic ground at dinner time...interrupting our evening meal! This is as close as you can get!