I thought the same thing. My back yard is full of huge rocks. Nothing quite that large, maybe 1/3 of that size. A few doors down there is a boulder twice as big as the O'Hare one.

I'm speaking in volume. I'm not sure of the mass of these boulders.

In chicagoland, yes. For someone who moved there from California, it was strange that rocks hardly larger than a human warranted school field trips and plaques. Perhaps it is geologically cool, but I was unimpressed as a 6th grader. https://live.staticflickr.com/65535/53236492797_60069bde90_b...

Dunno, but I haven't ever come across one on my property.

Medium-rare I would guess

Not from the look of it.