I know the area well. I'm in LaPorte county.
3/4 grooved axe and a very nice one. Somewhere between 8000-2000 BC
It could have had a number of uses.
Here are a couple of links on axes that will clue you in a bit about them:
That is exactly what we were looking for and wow that is fascinating to think it’s that old. I like the idea that this may have been used for ceremonial purposes.
My dad grew up just west of Crisman Rd on Melton Rd. There is a Best Western now just next to where his house used to be.