Not listed

[+Harry Dolphin 390]

Hiking on the Four Birds Trail, near Split Rock Reservoir, in the Jersey City Watershed, NJ.  Not listed on Geocaching Benchmarks.  The circle and letters are engraved into the post, but I could not read them.  Coords: N 40 58.503 W 074 26.578.  Just wondering what it is.  

[mloser 0]

My guess is property corner.