MBB and Craig--Craig offers some excellent advice and insight, although I would differ on one historical point. It isn't quite accurate to say Raven Fork was untouched by man. There's actually an old railroad grade which reaches up into the gorge a way from the Cherokee Reservation end, and a goodly portion of the watershed was logged. Indeed, the trail from Smokemont was originally built to carry in supplies for timber cruisers and loggers. Anyone who is interested in details on the logging history might want to look at Tom Alexander's delightful book, Mountain Fever.
That being said, Craig is exactly right in suggesting it is a majestic and beautiful area. It is also probably the most remote in the Park in terms of trail access, with no trails paralleling the stream and only one lateral trail penetrating the drainage at all.
As for accessing it, there's no question that of the two possible routes--from Smokemont and then up Chasteen Creek or from Straight Fork--the Straight Fork trailhead and access is the easiest.
I would add a couple of historical tidbits. For some years after the Park was created Tom Alexander took guests at Cataloochee Ranch in to Three Forks for camping and fishing. I had never thought of it until now, but that suggests the Park didn't have designated campsites in the 1930s and 1940s. Of course Alexander butted heads with the Park on more than one occasion, but I don't think he would have camped if it wasn't permitted. There's a small photo of the camp at Three Forks in my book, Fly Fishing in the Great Smoky Mountains National Park,
along with a much larger one of Tom's wife, Miss Judy, with a mess of Raven Fork Trout.
One final thought--Enloe Creek and Raven Fork upstream from Enloe Rock are both speckled trout heaven. Should you penetrate far enough to reach Three Forks, you will be at what is arguably the most lovely pool in the entire Park.