Brant are almost entirely a coastal species and is expected to be found in the Smokies on more than the most exceptional of circumstances.
The one record for the Smokies is of an apparently ill or injured individual at a pond in Elkmont in late October, 1939 (Stupka 1963) that remained for several days.
References:
Stupka, A. 1963. Notes on the Birds of Great Smoky Mountains National Park. University of Tennessee Press, Knoxville.
Gough, G. A., Sauer, J. R., Iliff, M. Patuxent Bird Identification InfoCenter. 1998. Version 97.1. Patuxent Wildlife Research Center, Laurel, MD.