http://www.armymwr.com/
I'd start there. Just in case you don't know what mwr stands for it's morale, welfare, and recreation. If you can't find anything there. Just google mass mwr, and it should pull one up for your closest military base. Call and find out. Thing is though, most likely you're going to need a military ID to play on any base. Since 9/11 they don't just let cilivians on bases, not without someone who's got a valid military ID.
Good luck.