It's too late to put a finger in this dike, it is long gone.
This dam is believed to have once been part of a gunpowder mill
that was built in the 1700's. The presence of gunpowder mills in
the area is one plausible explanation for the Gunpowder River's
name. Ruins of these two water-powered mills owned by John Rowe and
Son's in the mid-1700s can be seen along the Panther Branch
Trail.
According to an 1850 census, the company's gunpowder mill
employed four workers, produced 1,800 kegs of blasting powder and
received $4,000 in capital. On July 7, 1874, however, the powder
mill blew up in an accident.
(http://dnr.maryland.gov/publiclands/hereford.html)
If you look closely, you can still see these ruins today. The
old mill race is still visible from the dam where the cache is
hidden. Please do not disturb any of the stone foundations.
Hope you enjoy the hike and learning about this little known
piece of local history. If you know anything more about the area, I
would enjoy hearing about it in your post.
Be sure to look for other caches along this trail. Be prepared to
make a stone-hopping stream crossing, and to pick your way across
several muddy seeps. Hiking boots are recommended