My parents would take the family on hickory nut runs in the fall and asparagus runs in the spring (SE WI).  Put down the tailgate on the station wagon , we'd sit on that while Dad would cruise the countryside hitting hot spots he had memorized.  It was something to do on a Sunday afternoon.

Although the trees/plants were on the roadside, some farmers would get upset and sic their dogs on us, or fire shots in the air to scare us off.  We'd scramble back onto the tailgate and mosey off to the next cluster of trees/plants.

I remember sitting in the basement, cracking hickory nuts and extracting the meats for my mother to use in one baked thing or another.  It took a pretty good whack from a hammer to bust their shell.  Don't hit it square enough and the nut becomes a projectile.  It was hazardous duty.

We had a couple bitter hickory at our home on the Rock River.  Squirrels didn't even take 'em.

I've got two black walnut in my yard and I've so many nuts it's an ankle-twister to walk across my yard.  Never thought of trying to get at the meat of those things...one of the most impenetrable objects known (yet squirrels get into them.)