I am not sure what map they are using, but I snipped the following off of Peakbagger:
![[Image: 8.png]](https://i.ibb.co/xjRy46N/8.png)
I believe I found the marker close to the number 36. I am guessing that identifies a section of a grid.
Edit: Per wyethia's comment below stating that the "1/4" on the marker indicates it would typically be found "halfway along the boundary of the section", I checked the GPS coordinates I have for the marker with an overlay of this map and satellite imagery in CalTopo. Sure enough, the marker is actually at the midpoint of the northern boundary of T 18 1/2 N... just a few feet off on the east side of old 4WD trail that is depicted.
I believe I found the marker close to the number 36. I am guessing that identifies a section of a grid.
Edit: Per wyethia's comment below stating that the "1/4" on the marker indicates it would typically be found "halfway along the boundary of the section", I checked the GPS coordinates I have for the marker with an overlay of this map and satellite imagery in CalTopo. Sure enough, the marker is actually at the midpoint of the northern boundary of T 18 1/2 N... just a few feet off on the east side of old 4WD trail that is depicted.