Hello,

I can set your mind at ease, because these are not symptoms of oak wilt.  I cannot zoom into any of the pictures to give you more information on what is going on, however.  Are the black areas on the trunk holes?  If you would like to upload a few pictures of the symptomatic leaves and the trunk discoloration close-up, I would be happy to give them a look.  

Otherwise, I will attach an article on oak wilt, as well as an article on how to water established trees.  Once trees begin exhibiting signs of stress, they can become susceptible to other pest attacks.  Making sure your tree has adequate water during this drought will go a long way in preventing stress.

https://extension.umn.edu/planting-and-growing-guides/watering-established-trees-and-shrubs#measuring-tree-root-spread-1261762

https://www.canr.msu.edu/news/smart-gardening-to-prevent-oak-wilt

I hope this is helpful.  Thank you for contacting Ask Extension.

Ruth

Hello,

While I don't believe this is oak wilt, I am concerned if you have holes in the trunk.  I am not able to see what those look like.  I think it would be a good idea to consult an ISA-certified arborist  who can come to your site and see the tree.  There are borers that can cause serious health problems for oaks.  The following website provides a list of ISA-certified arborists in your area.

 https://www.treesaregood.org/findanarborist

Thank you for contacting Ask Extension.

Ruth