That was years ago, when they had a two week limit. (And a lot fewer loops) Now, if you've got the money (and the reservations) you can stay as long as you like!! (Provided it's not more than nine months - but who wants to stay more than that? I DO!!! )
You can only have a reservation for 30 days at the Fort. If you want to stay more than that you need to do a second reservation and they will link them together so you can stay on the same site. You just have to go to check-in and pay for the next 30 days.