Hi,

Oak issues can be hard to diagnose because they often look alike. This looks like a combination of anthracnose and oak leaf miner, but for a sure diagnosis to exclude oak wilt I suggest you consult with a certified arborist.

Oak wilt, anthracnose and leaf miner are all discussed here:

https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/oak/

The sites below are about oak leafminer. If you look closely at your photos some leaves have small holes in them, though not as dramatic as those on these sites. The first site has a photo that resembles the damage to your tree:

https://insectid.wisc.edu/2014/05/08/oak-leafminer/

https://bygl.osu.edu/node/1576

If you want an arborist to visit and look at the tree, you can find one here:

https://www.treesaregood.org/findanarborist

Good luck.



You're welcome.