We stayed in Bridge Bay in the middle of June at site #282. This site butts up to an open field which for some could be a draw back because there's little privacy but for us we got views of the Lake which were wonderful; we were able to sit outside and enjoy the sunrise over the Lake.
The Facilities are nice with potable water and sinks to clean dishes. There's also a few trails to hike and explore. We had an Elk walk right into the field towards sunset and graze. I'm only rating 4 stars because It's a little far from things like Old Faithful and Canyon Village, but we would stay here again.
Yellowstone is always worth the visit if presented with the opportunity and this is a really nice campground.