Yellowstone National Park Visit and Itinerary 

I visited Yellowstone National Park for six nights and stayed at Fishing Bridge RV Park Campground.My itinerary worked pretty well with having a RV and wanting full hook-ups but I also have some itinerary recommendations.
I recommend a 6 or 7 day trip. If you are staying in a lodge or dry camping I would stay 2 days near Old Faithful and take in all Old Faithful and the surrounding geyser basins have to offer. I recommend 3 days near Fishing Bridge to see wild life towards Lake Butte, Fishing Bridge if the trout are spawning, go to West Thumb Geyser Basin, and see the Lake Yellowstone Hotel as well as the other amenities at Grant Village and Lake Village. The marina is also in this area if you have a boat. You can also explore Canyon Village where the Grand Canon of Yellowstone is as well as see the Norris Geyser Basin.(Norris Geyser Basin has about 3 miles of board walks so pace yourself accordingly. The “Grand Canon “ also has lots of trails but you only really need to see 2) You may want to see these 2 features on different days. Finally I would stay near Tower Roosevelt for 2 days. From here you can explore Mammoth hot springs and the upper loop in a day and have time to look for wildlife in Lamar valley in the mornings. I think moving lodging would reduce driving time and make your trip more relaxing but I have not tried it.