I found this today, in this link,http://www.fs.fed.us/r9/mnf/sp/dolly_sods_wilderness.htm
"Special Notice: Many of the artillery and mortar shells shot into the area for practice still exist here. In 1997, a highly trained crew surveyed the trail locations and known campsites for shells. They found 15, some of which were still live. All were exploded on site. Many more may still exist and are dangerous. Since it is impossible to survey every acre of the wilderness, we ask that you follow the recommendations below for your own safety.
If you find an artillery shell, often called a bomb, DO NOT pick it up. Make a notation on a map, showing location, landmarks, and distance to nearest trailhead - anything helpful - and contact either the Petersburg or Parsons office of the Monongahela National Forest. We will know who to contact to get it removed. A good location by you is important to us so that we can find it again.
Please camp at existing campsites whenever possible. These usually have a fire ring and show bare ground around it.
If you camp at a place without a fire ring DO NOT create one. We cannot be sure that heat penetrating the soil will not set off a shell if it is close to the surface. Not creating a ring will also keep others from using that site and also being at risk. Use a backpacker-type stove for your cooking needs and enjoy a night without a campfire.
If at all possible, do not go around small obstacles in the trail. Going around will encourage others to go around also and soon we will have a new trail - one that hasn't been cleared for bombs. This put both hikers and trail maintenance people at risk of injury. Climb over, break off small branches, or whatever to get through. Our rangers will clear it as soon as they can."
The link from which I found that was an article in Cross Country Skier,http://www.crosscountryskier.com/destinations_white_grass_jan_2003.html/
I've been going there for many years and did not know this.