Agree, leaf serrations are too fine to be beech. At least the beech we have in NE WI and on my land. But yes, young beech really like to hang on to those leaves through winter. I also have tons of ironwood. They are pretty bare looking right now. Can't seem to remember if the really young ones can keep leaves though. Oddly enough, I have seen the occasional blackberry cane keep leaves a real long time. I might even go long odds and say it's not a tree. I did see a bunch of hazelnut brush on some land in Central WI today, they are bare for leaves. So not beech but something.....see how helpful that is!