Given that the egg sacks were green, it would seem they were caddis of some sort. At least one hatch chart for the Smokies lists "Grannoms" this early:
http://www.perfectflystore.com/hcsmokymtns.html
And they provide specific information about the bug, which they call a "little black caddis":
http://www.perfectflystore.com/littleblcadisinfo.html
They identify the Grannom that hatches early in the Smokies as
Brachycentrus occidentalis.
In regard to our Grannoms here in PA, one of Troutnut's bug experts, Lloyd Gonzales observes: "The collecting record shows two
Brachycentrus spp. for Huntingdon County [PA]--
B. numerosus and
solomoni"; and he identifies
numerosus as the species most commonly found on Penns Creek.
Eric, might the possible species difference at least partially explain the difference in hatch time, along with geographical differences?
Brian, The Nantahala is certainly a beautiful river; along with the Ocoee it was a favorite when I was a whitewater guide in North Carolina. We primarily frequented the lower reaches, taking out just after the first falls above the Nantahala Outdoor Center. I once saw a kid walking along one of the feeder streams to the Nantahala carrying a stringer of big rainbows. Obviously not a proponent of catch and release.