The sighting happened when Mark Holley, a professor of underwater archaeology at Northwestern Michigan University College and his colleague Brian Abbott voyaged across the lake in a ship furnished with sonar equipment with intent to examine old shipwrecks.
While combing Grand Traverse Bay they observed unique rock formations resembling Stonehenge, and rocks with strange engravings, one which Holley believes to be a Mastodon.
Learn how to diagram stone circles using PowerPoint. In 2007 Dr. Mark Holley discovered a Stone Circle at the bottom of the Grand Traverse Bay in Michigan.
PowerPoint presentation was made using INSERT Circle and line and ANIMATIONS Fade and Wheel commands. Zoom to 200% and hold down the Alt key to “fine tune the placements.