Stay inside the park!

First of all, Yellow Stone park is big and you should try to stay inside the park as much as possible. Roosevelt and old faithful are at the cover of each ring, so stay two days of each will save your traveling time. One of the lesson I learned last time was never under estimate the driving time in the Yellow Stone park and also back to your hotel before the sunset. The dark came suddenly due to the mountains block sunset easily and it was really scary to drive in the dark.