What to say to Yellowstone? It's hard to describe what this park offers. I saw my first bison at Lamar Valley, my first geyser - Old Faithful and I have never seen something like Grand Prismatic spring before. In between, things like Lake Yellowstone, Grand Canyon of the Yellowstone and the sheer beauty of the landscape are almost forgotten. Talking about the size ... Yellowstone is part of Wyoming, Montana and Idaho. It is huge in any aspect.