We am going on vacation with my parents for their 30th anniversary celebration. We are going to be headed to Denver, Salt Lake City, and Yellowstone for sure. Any thing we need to see for sure? Any tips? Best routes to drive? We know we want to see a lot of animals if possible, and pretty scenery..Going to see the Snake River and Tetons for sure. We are flying into Denver, and then have 10 days to spend before having to return to Denver to fly out. Thanks!