Alan,
While the Sulphur hatches may have come and gone on the freestone streams they will continue on the tailwaters in good numbers until late Oct or early Nov. They are a very important food source on tailwaters like the S, Holston. I would tie several types of sulphur imitations. Sparkle duns as well comparaduns are a good start. I would also tie some parachutes and some type of flymphs or wet flies. I have also had a lot of sucess with a Klinkhammer style fly. I use some combination of yellow bodies with some orange in the thorax for the fly most of the surface imitations. For the subsurface I use a redish brown dyed pheasant tail for the body and a yellow/orange mix for the thorax. Let me know if you need more specific information on the recipe for any of them.

Parachute
http://i68.photobucket.com/albums/i16/n ... 1184695310


Sparkle Dun
http://i68.photobucket.com/albums/i16/n ... 1184695951

Flymph
http://i68.photobucket.com/albums/i16/n ... 1184696134

Klinkhammer
http://i68.photobucket.com/albums/i16/n ... 1184696229

Cripple
http://i68.photobucket.com/albums/i16/n ... 1184696296