UPDATE...from the comments I have been told it is a Sandhill Crane. Went to my reference book and it sure looks like one. They are not suppose to be in the area. Although it is between their breeding range (Canada) and their year round range (Florida). Their winter range is Southwest Texas and Mexico, which would not put him here if migrating. Not sure what he is/was doing in the Smoky Mountains, may have just been stopping to eat along his way. The Stokes reference book does say they summer on prairies, maybe our pasture fields are like his prairie.
UPDATE to the UPDATE....please be sure to read the comment Ecobirder posted for me. He has some great information about this bird. Ecobirder's blog is always loaded with information about what he is posting, a great blog to visit. Thank you Ecobirder.