Tradition or folly?

Reader Chris writes:
Your recent blog post showing a "prayer seat"-type structure that was not old [see here - pwax] reminded me of this little thing I found in the Franklin State Forest. It is near a hilltop in a treeline facing a big clearing where power lines cut through the woods. I looked at the rocks carefully and there was no charcoal or any indication there had been a fire there. There were pine needles and leaves under the rocks, they have not been there long. The last picture gives some sense of the setting. I have entertained the thought that it is a recent Indian thing but suppose it could have been put together by anyone for any number of reasons.