In northern Minnesota we are at the extreme NW range limit of this species. Around here, any tree that is big enough to climb can be pretty much guaranteed to have substantial heart rot - to the point where I have yet to find a tree I consider to be climbable. The flip side of this is that two of my favorite wild edible mushrooms, the sulphur shelf (Laetiporus sulphureus) and Hen of the Woods (Grifola frondosa) seem to be only found on northern red oaks around here. Both of these are heart-rot fungi.

In much of Minnesota and Wisconsin, northern red oak hybridizes freely with northern pin oak (Quercus ellipsoidalis).