Ki,
That picture of the Indian Head Rock is too cool! Watch some of the KGC guys make something out of that or the Spanish trail guys! If I had wanted to get someone into that area I would have mentioned the (remarkable) Indian Head Rock! I hope this is close to where you have found the other items. There are trees out in the west that have Spanish carvings in them that are way older that when Swift was in KY, so i won't be too skeptical of the beech trees. I know where there is one that you had to climb down to get to a ledge (near one of the Indian mines) that has not hardly changed in diameter in over 30 years, so it is plausible Swift may have carved those letters. The growth of trees depends on a lot of things like amount of water they get, minerals, shade, sunshine, etc. and in mountainous areas some places lack several of the needed ingredients...lack of which means slow growth.