If ya include the Black Mountains crosschain, and I think most do, that maximum would be 6684 feet.
I was using the highest point on the Eastern Continental Divide, on the spine of the Great Smokies, as my reference point. My home is located on that Divide. The rain on one side of the roof flows to the Atlantic, via the Chatooga and Savanah Rivers. From the other side, it flows to the Gulf of Mexico, via the Little Tennessee and Mississippi Rivers.
John / Billybob