If you don't know a trustworthy doctor, ask an ER nurse.
They see not only the docs working in their ER, but get a good look at the responsiveness, demeanor and care of the docs who take "call," so have a pretty good eye for the good docs.
One caveat—whether urban or rural, ER nurses typically common things, so they do not have the training or experience in identifying or treating the exceptional cases. Sure, they see some "one off" sensational and weird cases (like the guys that put lightbulbs where they don't belong), but that does not translate into the acuмen necessary to handle the "sleeper" cases that require speedy insight and special handling (e.g., back pain that is a dissecting aneurysm, not the usual narcotic seekers complaining of back pain).