Begin your journey by parking near the Beech Trailhead. The parking area is large enough for two or three vehicles. After hiking a short distance on the Beech Trail (blazed with yellow diamonds) you will find that the trail parallels a paved road before turning back into the woods. At the Beech Trail sign, take the path that goes to the right. This is actually an old access road that leads to the structures at the posted coordinates.
The buildings were most likely erected by the National Park Service with the Conservation Commission of West Virginia as the sponsoring authority when many of the stone picnic shelters and fireplaces were built in the late 1930's. Construction of the dam by the Works Progress Administration began in 1940, but I suspect that the buildings were already in place by that time.
While I am uncertain of the originator, there can be no doubt as to their use. The Mining Engineers Handbook written by a staff of specialists under the editorship of Robert Peele, Professor of Mining Engineering in the School of Mines, Columbia University, published in 1918, details the techniques for safely storing explosives and blasting supplies. The buildings were constructed of double walled brick to make them both fireproof and bulletproof and had to be well ventilated. You will see the ventilation holes on top and near the base of each structure. Blasting supplies (blasting caps and fuses) and explosives had to be stored separately. When selecting a location for the magazine, the local topography was taken into consideration by placing it next to the hillside to take advantage of the natural protection. The brick walls of the structures were lined with two by two inch nailing strips, covered with 7/8 by 6 inch boards to form a lattice work. The purpose of the lining was to keep stock away from the walls and assist ventilation. The doors were constructed of 3/8 inch boilerplate, backed with three thicknesses of 3/8 inch hardwood, which would stop a bullet from a U.S. Springfield rifle. A couple that live near the park told me that the buildings were still being used as late as the 1960's.
The building you are standing at, the smallest of the three, would have been used to store blasting supplies. A close examination of the door, which has been welded open, will reveal a few shards of the wood that would have been used to line the interior. The bolts that held the wood in place still remain. Count the bolt heads on the exterior of the door and add them to 37. This will give you digits A and B of the latitudinal coordinates of the final cache:
N 40 32.5AB
Next travel to the low flat roofed building. As you can see, there is no iron framing around the doorway of this structure. Since steel or any metallic tools that could cause a spark could not be stored in the magazine, this building was probably used as a utility shed. As you are standing at the the doorway look inside at the left and rear walls (no need to enter the building). You will see small holes in the brick near the top of the walls that provided ventilation. Count the total number of holes in the left and rear walls (only count the holes that are still open) and add them to 4. This will give you digit C of the longitudinal coordinates:
Finally, make your way to the largest of the three buildings. It’s size indicates that it would have been capable of storing between 15 and 20 thousand pounds of explosives. As you peer inside, carefully inspect the right wall and you will see several of the 7/8 by 6 inch boards that made up the lattice work still attached to the wall. Count these and add this number to 18 to give you digits D and E of the longitudinal coordinates.
The cache is a .30 caliber ammo box placed with permission of the West Virginia Division of Natural Resources, Parks and Recreation section. The hike to the cache and back to your vehicle is slightly under a mile and a half. I have updated the attributes of the cache to designate it as Not Child Friendly: for the most part, the trail is very safe, however, there are a few places where the trail is narrow and there is a steep drop off into the Tomlinson Run gorge below. If your child is old enough to safely stay on the trail, the only deterrent would be the length of the hike. This will be determined by your approach to the final. There is a much easier way to get there, with the terrain being a lot less challenging, but it will require a longer hike of approximately 2/10 of a mile.