Gatlinburg is less than 4 hours from me, and I have known it not to be very veg friendly :(

Check happy cow and see if anything new has posted around that area. Knoxville is an hour away and Asheville is around 1.5 hours away (great vegan food there!). Google their tourist info and see what restaurants they list. Any steakhouse you visit you could always get sides like a sweet potato w/out butter, steamed veggies, etc... Urban Spoon had 3 listed. Here is an article: http://www.pigeonforgetncabins.com/pigeon-forge-vegetarian-food/
it's always a start. Mellow Mushroom is a great choice b/c they have vegan food (pizza with daiya cheese).

Good luck and enjoy the area! It is breathtaking!!!