If I had seen this post this morning, I would have looped over there and given you the site numbers! There is a good aerial map somewhere on this camping board that has the site numbers, but when you request your loop, just put Loop 300 on the outside. When we get to the Fort each visit, we drive around and if we see a site we like best in that loop or where we can get a better satellite signal, we just call the front desk and tell them we needed to move to a more accessible site.
We've never done that, but we know a ton of people that do it and as long as no one is in the site and it's been cleaned by the maintenance crew, they normally don't have an issue with it.