A friend's father found this several years back, it took a tractor to get it home, when he found it, it was face down when they flipped it the grind stone on top was underneath it.
Hope you guys enjoy the photo as much as I do.

That is a dandy.

Wow, that is quite a find!

That's cool to find the mortar and the pestle together.

That is a great find. Like they say if only it could tell the stories of the past.

Wow

I would bet they flipped it over to keep the water from getting in and freezing it over the winter , when they were ready for it again, flip it back over.

one year they didn't return in the spring and there is sat.

Awesome find!

Very cool stuff!

I found a good size one about 100 lbs and it was upside down, not sure the reason they flipped them, but I figured it must be the weather as well.

How big is this? Hard to tell from the pic.

How neat is that?!

It's big take two to load it on a loader.

That makes a whole lot of sense. I have found close to 70 tools on my farm, most for making pemmican and other food prep. There's 3 huge boulders at the camp site, by my back barn. One has 14 mortars worked in it. One has some polishing on the exposed surface, but mostly looks like a long, flat granite slab. I should try flipping it.

Keith

That's a beautiful mano and metate set. I wish I had one that nice.

Keith

I noticed mowing last week, that a lot of rocks worked there way out of the ground, below the main camp site, right above the closest spring. I should go examine them before the plants over grow them.

Keith

The best one I found was towards the bottom of a bluff the deer/ cattle had wore a deep path and just the corner was showing, I was turkey hunting, anyway I felt like that corner showed like it had been altered I went back a couple months later and dug it up, it was upside down and is awesome to see, I've tried to get a decent picture of it but they don't even begin to do it justice.

I have what was once a hammer head as a door stop right now. Has a nice smoothed out groove where it was lashed to a handle

very cool.

Maybe the Blackfeet flipped them over so that the thieving Pawnee saw it as just another rock and left it be.
(If any of y'all are Pawnee, feel free to just switch the names around.)