The invasive Emerald Ash Borer has made it's way to our area. Although I recommend getting advice and treatment from a board-certified arborist if you suspect your trees are infested, the following may help you identify both an Ash tree and the Emerald Ash Borer.
This is an Ash tree in my own backyard. I'd estimate it's about 40' tall.
Take a close-up look of the leaves of the Ash to help you identify:
If you start to see small, D-shaped holes, this is an indication it's time to call an arborist. The adult beetles create these holes as they exit the tree. But these holes are small and considering the heighth of the tree, there are a couple of other ways to diagnose the problem. For example if you notice increased woodpecker activity in your yard.
Thinning at the top of the canopy and new shoots at the base are another good sign to watch for as the holes can be quite difficult to spot as are yellowing of branches and/or die-off of some branches.
If you look closely, you will see the evidence of the larvae that bores a maze-like pattern through the soft bark. Once an infestation occurs, the Emerald Ash Borer can devour entire communities of ash trees. The trees can die in as little as three years.
I, personally, have used Heartwood Tree Service in Charlotte but there are several other board-certified arborists in the area should you need an expert opinion.
As I said, I'm not an expert when it comes to tree identification and diagnosing issues but I found this helpful website from the NC State Extension. https://projects.ncsu.edu/cals/plantbiology/ncsc/tnc/acer.htm