There are black walnut trees all over downtown Traverse City neighborhoods. This tree does not appear to be native according to the US Forest Service: Juglans nigra L.
-Native range of black walnut
but it sure has naturalized itself wonderfully.
I've often thought about collecting these walnuts but was never sure about how they compared to the English variety you get in the store.
Supposedly they are wonderful as Hank from Hunter Angler Gardener Cook discusses at TheAtlantic: Black Gold: The Pleasures of a Hard-to-Crack Nut
Looks like I have a foraging project for next Fall!