Ohio Serpent Mound Lidar

Something from a little further afield. Starting with lidar survey produced by the Ohio Department of Transport. Coverting to .asc via the very useful LASTools and modelling slope severity in SAGA.
The Great Serpent Mound is thought to date to 1070 AD (CE if you like). I find myself as intrigued by the earthworks on the other side of the valley (not fully visible in this view). What looks as though it could just be a river levee turns through 90 degrees at its northern end and may be something much older. Ohio has some very interesting monuments which have benefitted from lidar research.