Sulphur nymphs aren't yellow like the duns but this yellow nymph has worked well for me on the Holston in the past:
Swinging soft hackle flies is quickly becoming one of my favorite ways to fish and this partridge and yellow should do the trick:
This CDC Sulphur emerger has taken a lot of fish for me on the Holston. I usually fish it as a dropper off of a parachute or comparadun pattern and the fish probably take the emerger more often than the dun:
And now for the Sulphur duns: This is a divided wing parachute pattern I've been experimenting with that takes me a long time to tie. I've never done extremely well with hackled patterns on the Holston but I'm anxious to see if the realistic wings will make a difference to the fish:
A Sulphur CDC comparadun followed by a deer hair comparadun. Both are definitely proven producers on the Holston:
A new pattern I've been working on - a burned wing Sulphur no-hackle. I'm excited to give this one a workout.
If we happen to catch a spinner fall, hopefully these burned wing rusty spinners will do the trick:
Besides the Sulphurs, which pretty much always seem to be hatching on the Holston, we've got a good shot at seeing some Blue Wing Olives. Most of these are the same patterns I tie for the Sulphurs except in Olive instead of yellow and one to two sizes smaller.Olive nymph:
Partridge and olive soft hackle with trailing shuck:
Olive CDC emerger:
Burned wing olive no-hackle:
Olive CDC comparadun and deer hair comparadun:

One thing's for sure, even if these patterns don't work worth a hoot, at least I can keep myself busy changing flies.