ModernMiner (and Malisa), approximately a year ago there was a long, detailed discussion of so-called Indian Trail Marker Trees here in the What-Is-It forum. Perhaps somebody here can find that discussion and post a link to it. (I can't do that for you because I'm not very good at searching for a particular "topic" on the TreasureNet website.)
What part of the world are you in? Around here ( upstate SC) these would be called marker trees. I know of two of these that are at or near old gold mines.