And if they really trust you, a licensed guide might take you out there on a winter day when the ground is bare. Then you can see for yourself the telltale depression where the ground has settled into the graves below.
The National Park Service acknowledges there are at least 100, maybe more than 200 Confederate soldiers still interred in the thick woods that cover the Culp's Hill area.
But the rangers don't talk about them on tours because of concern over possible vandalism.
Disturbing hallowed ground is forbidden, and even possessing a metal detector on the battlefield is against federal law.
Battlefield park spokeswoman Katie Lawhon explains that if someone unearths a bullet, it might have been lodged inside a decomposed soldier. Removing the bullet destroys the spot as a historical site forever.
The NPS leaves the bodies buried because current archaeological practice in all national parks is to disturb as little as possible, so that future generations will have intact sites available for study.
Public interest in the bodies on the battlefield was immediate following the fight 150 years ago, and photographers made their way to Gettysburg to record the grisly scene.
Since the 1970s, local historian William Frassanito has revolutionized the understanding of these photographs by finding distinctive rocks and other landmarks in the background to determine exactly where they were taken.
Frassanito also has determined that photographer Timothy O'Sullivan moved a body to pose his famous photograph of the dead Confederate sniper at Devil's Den.
In the days following the battle, Union and Confederate soldiers were buried near where they fell, some by comrades, most by burial crews in the week after the battle. The Union also mapped the location of the graves, still a reliable indicator of where the heaviest casualties occurred.
Eventually, Union soldiers were removed from battlefield graves and re-interred in the National Cemetery dedicated that November. A few Confederates also are buried there because the markers on their original graves had become illegible. Mississippi soldiers are buried among the Massachusetts men and Georgians lie next to Pennsylvanians.
All of the soldiers still buried on the battlefield are likely Confederates. Most families of the Confederate dead would wait for years after the war for private efforts to remove and rebury their relative's remains in the South.
In the case of the more decomposed bodies, the crews took only the larger bones; the smaller ones were left to fertilize the hallowed ground.
Still, over the years, additional remains have been found and reburied at the cemetery, most recently in 1996 when Confederate remains were discovered on Seminary Ridge.
Today more than 6,000 veterans are buried at Gettysburg National Cemetery, including veterans of the Spanish-American War, World Wars I and II, the Korean War and the Vietnam War.