Yellowstone National Park

Yellowstone is a unique place with its beautiful lakes, mountains, and myriad geologic phenomenon.   We've enjoyed touring around and seeing the flowing  rivers and boiling cauldrons of water and mud.  Exceedingly cool stuff to see here!  The crowds are challenging though, especially if you are coming from a park like Glacier or Crater Lake.   Really glad we visited,  but not in a big rush to come back unless it's not in the height of summer vacation season. 
We have definitely seen some interesting wildlife here and have experienced the Buffalo traffic jam= buffalo all walk or run  onto the road and block cars from getting by in both directions. This did allow us to take some excellent close-up pictures of various buffalo from all angles.  We saw a black bear with her cub also.