The other DrC has some very nice photos of Yellowstone, the Tetons, and wild animals at her blog here and here. It is worth your while to give 'em a gander.
The two national parks in Wyoming's northwest corner are a big reason why we - a pair of native Californians - ended up calling Wyoming home. It is world class scenery, for starters. Add in the thermal features which are the world's most elaborate and an unfenced wild animal habitat which you could think of as an alpine Serengeti. Plus the largest high altitude fresh water lake in North America.
The DrsC have visited 120+ countries and, with that as standard of comparison, there is really no place with everything northwestern Wyoming has to offer. It is unique and marvelous and home.