Hello Guys,
I'am new to the game of Geocaching, but as you can tell I'am a Surveyor with TVA. This corner that you have found is a TVA property corner. This is a standard type of monument that TVA used on most all TVA property corner that they set over the past 70+ years.
The numbers (5-34) start with the MAP number(5) of the reservoir and then the corner number (34) for that map.
Thanks for the interest in this type of monument. If you locate any more of this type on this reservoir or any TVA monument, please waymark the point and log with a picture and send me a message I will check from time to time.
There are thousands of monuments like this one over a SEVEN STATE AREA in the TVA service area.
Happy Waymarking!