Looks interesting. Did you get more pics? Close ups of the "arrows"? Are you in coastal Carolina? Or Western? You say deep in the woods, but was it off a trail or stream? Any other unique elements around? Looks somewhat old as the rock fungus is growing over the cross. Take a super close up of the "paint". Looks like a marker rock, but could be Boy Scouts 10 years ago or a colonial party 300 years ago.