|....................... .................... ...Fly Fishing Yellowstone National Park
New KISS Bug Series - Part 42
Little Yellow Stoneflies
KISS 101 imitating Stonefly nymphs is to remember they all crawl out of the water to hatch. They do not
hatch in the water. The nymphs crawl upon the banks of large boulders that protrude out of the water and
shed their shucks. The Little Yellows do this starting very late in the afternoons and on into the evenings
and off course, that's the best time for you to fish the nymph imitation of them. Just so I make certain I
mention it, the Little Yellow Stonefly nymph isn't yellow, it ranges from various shades of brown to tan.
Angie and I have experienced some very fine fishing in the late afternoons on some of the little fished fast
water streams in Yellowstone National Park fishing an imitation of the nymph during the Little Yellow
Stonefly hatches. The upper Gibbons River, Duck Creek, Grayling Creek, Middle Creek are just a few that
comes to mind.
All of the species of these two families of stoneflies live in fast water. They must have fast flowing, clean
water to survive. Prior to the hatch, the Little Yellow Stoneflies will move along the bottom from their fast
water habitat to the banks to hatch. Just as soon as they get out of water, they shed their shucks and fly
away. The best chance the trout have to eat them is during this migration prior to the hatch. Often, the
trout will actually intercept them along the banks.
These different species of Little Yellow Stoneflies hatch at different times of the year depending on which
species. Most of the Yellow Sallies, or species of the isoperia genus, hatch in the Summer. The nymphs will
crawl to the banks in the afternoons if it is heavily overcast. The later in the day, the better the fishing
usually is, but you can take trout imitating the migrating nymph anytime during the afternoon is a hatch is in
If you walk up to the bank and cast or if you walk up to the bank and wade into the water, you may have
spooked the trout you are trying to catch. Where the trees and bushes allow, you should first cast to the
banks from a short distance away from the banks. Bring the nymph on the bottom all the way back
to the bank. Remember, the trout do not have to see you to spook. If you are not careful, they can hear
you walking on the bank close to the water through their lateral line. Ease up to the stream as quietly as
possible without kicking rocks, etc. When you do get in the water, wade away from the bank about a rods
length and fish the nymph down and across allowing the nymph to swing back to the bank. This will work
much better than a up stream cast.
Continue to move downstream a foot or two each cast covering all of water along the bank. If you cast out a
few feet, say ten or fifteen feet using a reach cast that ends with your rod pointing towards mid-stream, you
can slowly swing the rod back in the opposite direction pointing it towards the bank. This will swing the fly
from several feet out in the stream all the way to the bank. In other words you can cover approximately
twenty to thirty feet of water each cast. Of course, this changes with the particular stream and stream
composition. If there is a run near the bank, you may only need to swing the fly a few feet.
You will need to make longer cast than you are probably used to making in small streams. You need to
keep the fly twenty feet or more away from you depending on the water. In shallow water you may need to
keep the fly thirty feet or more from you to keep from spooking the trout. Remember, the trout will be facing
you when you fish downstream.
Make sure you keep the fly on the bottom. If it is swinging up off the bottom mid depth or near the surface,
you are not going to catch many fish. Weight it down and keep it right on the bottom. When you pick it up
slightly off the bottom, the fly will swing towards the bank a few inches. Let it get back on the bottom
before you lift the rod again.