My Unknown Trees

I have 2 of these trees here and I've never been able to identify them. I think the bark is absolutely lovely on them. Once the leaves return, they form a very nice canopy.

When my daughter was in 7th grade a few years ago, she did a 7th grade leaf project in science class. It's quite a big deal at school , you identified & then pressed as many leaves as you could possibly find. She had leaves pressed everywhere. The leaves were then turned in with the identification and other pertinent information. I thought we'll finally be able to identify these trees, whenever they couldn't ID something they took it to school and the class & teacher worked on the identification. Well, except no one could figure out what they are. So if the ever popular 7th grade leaf project couldn't identify these trees who can :)