Ancient Mountain Structure

I found what appeared to be a crude shelter on one of my ridge hikes. The structure consists of a crescent-shaped wall of rocks on the right, stacked up to form a compressed ring with the large rocks on the left. A government archeaologist reviewed the photo and based upon the lichen growth and professional judgement he said its possibly several hundred years old. Hopefully we can visit the site in the future so he can look at it more closely. July 2007