Leafs look similar on all three but the acorns on the Sawtooth are way different. I can't really tell from the pic but your nuts look spikey. Chincs and DCO have no spikes.I have never had a sawtooth produce being 3 ft tall,
I think you nailed it! It must be an Allegheny Chinkapin.I think the pic in question is of an Allegheny Chinkapin. They do have a spiny shell like a chestnut and it appears that the leaves in the picture look to match. They are an early producer as well.
Look at this thread and it should show you some pictures of an older one:
https://r.tapatalk.com/shareLink?share_fid=1470359&share_tid=936&url=http://deerhunterforum.com/index.php?threads/ACs?.936/&share_type=t
https://r.tapatalk.com/shareLink?share_fid=1470359&share_tid=4094&url=http://deerhunterforum.com/index.php?threads/Which-Species-of-Castanea?.4094/&share_type=t
Sent from my iPhone using Tapatalk