I planted about 40 black walnuts seeds on my land last fall, hope to have good germination, they are spaced in a grid, 10 M between trees, might end up being too close, but I expect some will fail to grow.I have a relatively small black walnut, so they will survive in ND. Even after they were accidentally mowed a few times. Mine is located on the edge of my pond. Probably way wetter ground than I would have expected to find one.
Ive also got a 2 year old pecan area that are doing ok, and a 1 year old chestnut area. With our relatively mild winter, hopefully everything made it through. Likely the chestnuts are the least hardy for this area.