I am a retired US Army officer and part-time guide at Gettysburg National Military Park.The Licensed Battlefield Guides of Gettysburg are licensed and regulated by the National Park Service.They are the ONLY individuals legally allowed to conduct visitors around the park for a fee! Guide fees are established by the Superintendent of the Gettysburg National Military Park acting as the representative of the Director of the National Park Service.The basic battlefield tour duration is two hours.