that people have been out there more than once scouting locations. It seems they specifically were interested in the location where Lincoln and McClellan had their famous meeting. The battlefield itself is one of the best preserved of the nation's civil war battlefields so if they want to film battle scenes for Antietam they pretty much can in most areas of the park. It seems there is concern about protecting the park as there was some damage at Gettysburg during filming of the film Gettysburg and the Park service doesn't want to see a repeat of that.