We knew we'd want to stay at Yellowstone for two days, since it's such a huge place. And I'm glad we did - for all that seeing Old Faithful and the Lodge was cool, the drive to that location was fairly sheltered, and we couldn't see much. So day 2 of our Yellowstone trip gave us a lot of beautiful scenery and wild animal sightings! We also went through the Grand Teton National Park, which is adjacent to Yellowstone, and checked out the breathtaking mountain views.
This is the town park in Jackson, which had four of these entry arches made of elk antlers, some of which were over 5' long!