There was only one car ahead of us when we arrived at the East Yellowstone gate. We didn't have to pay an entrance fee since we had the senior pass. The fee is usually $30 a vehicle for a 7 day pass. The Senior Pass cost $20, so already saving money with that.
The road from the East Entrance climbs up over Sylvan Pass, past Sylvan lake, and then down again to the North East side of Yellowstone Lake. The drive is very beautiful and there was a lot of snow on the mountains through the pass.