Let’s face it right away, 2 days to experience both these national parks is short. But if you don’t have more time and still want to see the main highlights, it’s feasible! You just need to be well prepared. This suggested itinerary starts in Gardiner (Montana), close to Yellowstone’s North Entrance. You will go all the way down through both national parks until Jackson (Wyoming) on day 1 and then all the way up back to Gardiner via a different way on day 2 (first night in Gardiner, second night in Jackson and third night in Gardiner). Roads are in good condition and (most of) the main sights are very close to a parking, which make these great national parks easy to visit. All the attractions are clearly marked and the visitor centers provide very good maps of each site. Note that this trip can only be done in summertime, when all the roads are open.