The getting ahead effort has made for a situation I am having difficulty with. I am currently stacking by species. I have a mix of Red Oak and Walnut that has been split for over a month. Once the Red Oak dries out a bit, it looks an awful lot like Walnut. I may be a little color blind, but I don't think that is the problem. Any other indicators you can point out to differentiate would be appreciated. Smell is out of the question too, since the dried logs have little to know odor.