Depends. My uncle is the only doctor of any kind within an hour's drive for a tiny Appalachian community. He does better than most of his patients, but by general American standards he's making middle-class money, and not "upper middle class" either.
(On the other hand, up on top of a mountain that's enough to afford a six-bedroom lumber baron's mansion, and the kind of recognition where a local didn't want to take my check until I mentioned my uncle's address (not even name!), and then it was "Oh, you're staying with the Doctor? Why didn't you say so!")