Back from another trip to the Black Hills. These copper nail/washer bench marks were standard intermediate points for USGS lines dating back to around 1896. These two, however, are from 1955. On the 7.5-minute quads they usually appear as an "X" with an elevation and not with the "BM" initials which are the disks in concrete.
The first one was listed as being in the root of a 24" pine which looks about the same size today. The second one was listed as being in a 40" pine. This pine is also being uses as a BT for a nearby quarter corner.
These copper nail/washers are a bit more challenging to find since you typically need a good lat/long to start from and a metal detector combined with luck that the tree is still there. I have not found where USGS blazed a tree for a copper nail, but they sometimes did for the actual permanent bench marks. I have seen USGS blazes for the 1898 bench marks. Most are now grown over.
These copper nails were almost always placed in a root and noted as such. There was a small blazed area in the root.
Cool. Very interesting finds Jerry. Was the 40" pine a bearing tree before it became a bench mark? (if so, did the USGS note it was a BT when they set the nail?)
There was no mention by USGS in their notes of the 40" BT if it was one before they set the nail in it. I would say that it probably was already there. I was off by about 100' in my search location, but that big tree really stood out.
I have never seen the USGS aluminum tags that you find with the nails. The arrow on the quad below shows the location of the 40" pine near the 1/4 corner between 16-17.
Like finding a needle in a haystack. Good Job!
Dale Yawn
Savannah, Ga.
