Iron Mtn was in the Tri-Cities area, but I don't think he is actively building now. There is a 3D range near the Pigeon Forge/Seveirville area, but can't remember the name. It's mainly wheelie shooters, but is a pretty good course. Alex Roche (Bear) and I've shot the course, he could likely give you the name or directions. Also Ye Olde Fartes has a monthly shoot which would be about a 90 minute drive from Townsend, don't know if it would be the same time as when you are there.
On another note, in Townsend at about the time you are going, (AND I"M NOT MAKING THIS ONE UP) the fireflies become synchronized. Sounds odd and I've never witnessed it, but I have friends that go there every year to see the phenomenon.