Great Serpent Mound, mystery of southern Ohio

I've been looking into the mysteries of Serpent Mound as research for my next book. I find there is so much more there than I had dreamed about before. The mound is apparently in a huge, ancient crater. The egg in the serpent's mouth points toward a cliff where a stone, thought to have once been upright, has been located. Evidentally that stone, which must have fallen over the cliff, will be restored soon as part of the phenomena of the mound. Some believe the mound area is a unique vortex in the earth that promotes health and well being in the people nearby. I have also found reports of crop circles found in the area in 2003.

My research is for a new book, tentatively called The Bite of the Serpent, which will be set in/near Sinking Springs, Ohio