I need help telling northern red oak from southern red oak during winter.

[Hogfan]

I found this forum while searching for help identifying black oak. Thanks to the pocketknife bark peel trick, I think I can now do that. The yellow under bark is pretty striking. 

But most of the red oak Identification guides suggest looking at the leaves and that's obviously not possible in the middle of winter. I live in NW Arkansas and we have both southern and northern red oaks as well as black oaks here. So, anybody got any fool proof tips to tell northern from southern without leaves? My involvement with them is just for firewood, but I just would like to know. 

[KEC]

I can't help with telling Northern RO from Southern, but Black oak has chunky looking bark, at least on bigger trees.

[ESFted]

Northern oak is covered in snow.  Southern oak...not so much :D Sorry, couldn't help myself.

[firefighter ontheside]

I think the bark is your only hope without leaves.  Try this.
Northern Red Oak vs Southern Red Oak: Identification - bplant.org

[kantuckid]

I have both trees on my small forest in the Daniel Boone NF/Red River Gorge Geologic area. 

[curdog]

I've heard the ridges in NRO bark described as ski slopes.  Usually darker colored ridges and lighter gray colored valleys. But learning the buds is going to be the best option for winter tree id 

[Hogfan]

I think the bark is your only hope without leaves.  Try this.
Northern Red Oak vs Southern Red Oak: Identification - bplant.org

The pic of the bark on the sro is such a small part of the tree that basically, it could be a black oak just as easily as a sro. Do nros  exhibit the same white horizontal banding as sro? 

[WDH]

Northern red oak bark has silver longitudinal streaks.  Very distinct silver streaks.  Ski-slopes is a good description.  Southern red oak does not have the silver streaks.  I do commonly see the white horizontal banding on southern red oak.  I can easily distinguish the two from the bark. 

As to acorns, the shallow saucer like cup on northern red oak is distinctive.  Southern red has more of a bowl shaped acorn cup, not saucer like. 

[Hogfan]

I think I can identify nro pretty easily. It's just the sro that I'm struggling with.  So far,  everything either looks like a nro or has the yellow under bark indicating that it's a black oak. 

There aren't any acorns right now,  so it looks like I'm stuck waiting on leaves to emerge. Once I'm able to match the leaves with the tree,  I'm hopeful I'll be able to recognize the differences in bark as well. 

Oh well,  I've made great progress figuring out which hickory is which this winter.  I guess I'll look forward to Spring for the oaks.