Yes, yes, of course there's Bison everywhere in the Park. But of course you need to keep your distance, especially with the little ones around.
The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, and the third largest in the world, and it's oh so pretty.
Be sure to stop at Yellowstone Lake to view one of the famous thermal features in Yellowstone National Park. Word has it that it got its name from early visitors to the park who would fish for trout while standing on the rim of the cone.