yellowstone park-i want to camp in one place, where should I

I believe that about half the campgrounds are operated by Xanterra and take reservations and the rest are operated by the Park Service and do not reserve. I would try for reservations 1st but if none available, I wouldn't be afraid to show up at 1 of the non-reser. campgrounds(such as Mammoth) during mid to late morning. Be aware that the Park is huge so a centrally located campground, such as Canyon, might be good.