I know some forums look down on posting in old threads, but I might can help shed light on this issue.
North Georgia's little Chernobyl: along with the abandoned mines and all the marble in the ground being a possible carcinogen, this is one of those
things the real estate industry would rather you not know about. I live about 30 miles from Dawson Forest and grew up hearing stories about the place.
My dad used to ride horses in the area and it's still a popular spot for riding, four-wheeling, hiking and camping. As already said there's not much
left to see topside, but I've been told that at one time you could drive cars down a tunnel until you reached water from where they flooded the base.
One of my dad's friends once went in there with SCUBA gear and from what he told him there is/was indeed quite a bit of trucks, desks and other
equipment still in the labs. Now before y'all go off on a salvage mission it's probably worth noting that my dad's friend died of cancer a few
years after that.
A local paper has a nice, if somewhat hard to read, article on the place;
y'all might also want to check out the Dawson News and Advertiser as well as the local historical societies or libraries. From what the article says
it seems they were doing much more than trying to make a nuclear-powered aircraft, though this seems to be more the university's doing than Lockheed.
Their story about the government screwing with our ecosystem don't stretch credibility quite as much as some of the alien theories I've read in this
thread, but I'm still a bit skeptical as I've never heard of such things from local folklore (and believe me we've got some pretty wild theories
going around over just what the government was doing in there.)
There's also a good many caves along the Etowah River in that general area.
Theories I've heard of concerning the Dawsonville facility:
1. A few UFO stories, of course.
2. Deformed animals, plants, etc. Most of the folks who hunt in the area reject these claims.
3. They actually succeeded in building a nuclear aircraft.
4. They were never trying to build a nuclear aircraft at all but instead built/were trying to build a nuclear
spacecraft (Orion Project,
anyone?

)