please see editional  photo

additional photo

additional photo

Hello John

Thank you for the additional photos and your patience at this busy time of year.

I had one of our Foresters look at this. This could be one or more conditions. Submitting samples to MSU Plant and Pest Diagnostic lab can confirm what it is, since it needs a microscopic look to confirm. There is a fee for analyzing a sample, often around $25.

Here is the lab website where you can print off a sample submission form and find directions, fees and mailing information- https://www.canr.msu.edu/pestid/

Possibilities are iron chlorosis, mite galls, or spider mites, or oak leaf blister.

Some references-

Oak leaf blister

https://bygl.osu.edu/node/805

chlorosis caused by too high soil pH-
https://www.extension.purdue.edu/extmedia/BP/BP-27-W.pdf

Oaks prefer  soil pH between 5.5 to 6.5. If your soil pH hasn’t been tested, you can get a soil test here which shows pH, nutrient levels and organic matter. It will give you recommendations according to the results:

https://www.canr.msu.edu/news/soil-testing-returns-through-msu-extension

Be sure to keep your tree watered if rains subside for more than 2 weeks. Here is  watering info for you to keep on hand: https://extension.umn.edu/planting-and-growing-guides/watering-established-trees-and-shrubs#when-to-water-trees-and-shrubs-1261760

Regards, Laura S.