We're in the Catonsville, Maryland area. We noticed some dry rot around the base of the large silver maple in our backyard.

I'm looking for any input/references anyone might have to finding an actual tree DOCTOR. Emphasis clearly on someone financially motivated to give advice and service on keeping a tree healthy, not a guy showing up looking to make money on a big chop-it-down job. I think I can find the latter with little trouble. It also had some dry rotted limbs come down recently that came from near where it was trimmed a few years back.

I know the silver maples aren't supposed to last forever, but I'd be interested in keeping it around for as long as possible. Any thoughts?

Thanks,