Its a bit difficult to make out some of the details. Try lighting from a lower level so that the light only covers the stone and not the engraved part. It will really help us here on the other end. obiviously there is a SIX in roman numerals. I would say a river is on the right or a shoreline. and the trail on the left. Not sure about the three forks.
you can see its all details there...
and as you said,it is V and VI written on the map,in Roman letters it is 5 and 6,and but in Arabic letters it is 7 and 71.
I am waiting for your more comments.