Hello, Ted!

The maple is definitely exhibiting  symptoms of chlorosis. Chlorosis is the condition whereby leaves don't have enough chlorophyll; that's why they are not-so-green. Several things can cause chlorosis: nutrient deficiency in the soil, drought, extreme PH levels, or a combination of more than one of these factors. You can test the soil around the tree through MSU ( https://www.canr.msu.edu/news/soil-testing-returns-through-msu-extension) or with a kit available through home and garden stores. If through MSU, the test results will come with soil amendment suggestions. One thing you can do before any testing is stripping turf away from the tree drip line, mulching the tree with natural mulch (untreated wood chips are a good option) and giving the tree a good soak during drought. This alone may help your maple feel better. Obviously, the stripping, mulching and watering will have to wait till spring.

More on chlorosis and how to deal with it can be found here: https://www.canr.msu.edu/news/it_isnt_fall_yet_so_why_are_my_trees_leaves_yellow