Natural rock or stone tool?

[Beaglejuice13]

Found in the U.P. of Michigan sometime in the late 80's. I've always thought it was an artifact, but I'm not so sure anymore....Any help would be great on this one...

 

Amazon Forum Fav 👍

Upgraded Night Vision Monocular Digital Infrared Monocular Telescope for 100% Darkness with 8X Zoom - Grab it through Amazon!

[A2coins]

That is creepy and really cool at the same time lol