The best tailwater nymph patterns are small, sparse imitations of what dam-release rivers grow in huge numbers: midge larvae and pupae, scuds and sowbugs, Baetis mayfly nymphs, aquatic worms and eggs. Carry them in sizes 16 to 24, mostly black, red, olive and tan, and fish them near the bottom on 5X to 7X fluorocarbon tippet.
My first winter day on a tailwater, I showed up with a box full of size 12 freestone nymphs and spent the morning watching rainbows feed six feet in front of me while ignoring everything I threw. The angler below me was landing fish on a black midge I needed readers to see. Tailwaters run on their own menu, and the menu is mostly tiny.
You don't need hundreds of patterns, just the right ten, rigged so they reach the fish. Here's the list I'd hand a buddy heading to the South Platte, the Green, the Provo or the Bighorn. Everything below lives in our FFIP fly collection.
- Start here: Black Zebra Midge, sizes 14-18, the one fly I'd keep if I could only keep one.
- Smallest water, pickiest fish: Flash Midge Pupa in 20 and 22.
- Food that never leaves: Beaded Shrimp Scud for scud-rich rivers like the Bighorn.
- Dirty water or flow bumps: San Juan Worm as the lead fly.
- Fast, deep riffles: Black Perdigon with a tungsten bead.
What Makes Tailwater Nymph Patterns Different?
A tailwater is the river below a dam, and the water comes out of the bottom of the reservoir at a steady, cool temperature most of the year. That stable flow and temperature grows enormous numbers of a few small bugs, especially midges, scuds, sowbugs, aquatic worms and Baetis (blue-winged olive) mayflies. So tailwater trout eat small food all day and get very good at spotting a fake.
Tailwater trout also see a lot of anglers, which is why good tailwater nymph patterns are sparse, slim and dull, with just a hint of flash. For deeper tactics, read our guide to tailwater tactics for picky trout.
Which Midge Patterns Should You Carry for Tailwater Trout?
Midges hatch on most western tailwaters every month of the year, and in winter they are often the only game in town. Carry larva and pupa patterns in black, red and olive, sizes 16 through 22.
Black Zebra Midge Assortment
The Zebra Midge is a bead, a thread body and a silver wire rib, and it might be the most important tailwater nymph pattern ever tied. This dozen gives you four each of sizes 14, 16 and 18 with black beads. Fish the Zebra Midge as the bottom fly under a scud or worm, or alone under a small indicator in slow tailouts.
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Flash Midge Pupa
When the fish want it tiny, this is the fly. The Flash Midge Pupa comes in sizes 20 and 22 and adds a little flash to a slim pupa profile, which can earn a second look on heavily fished water. It's priced per fly, so grab a handful and fish it on 6X or 7X behind a heavier lead fly.
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Mike's Midge Pupa
Mike's Midge Pupa adds a wisp of CDC near the head, so it breathes and pulses as it drifts. It comes in black and olive, sizes 16 to 20. Fish it as a dropper under a small dry or swing it up at the end of the drift when you see trout flashing just under the film during a midge hatch.
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Bead Head Rainbow Warrior Midge Assortment
Lance Egan's Rainbow Warrior is a midge-sized attractor with a pearl and red flash body, and it's become a confidence fly on Colorado and Utah tailwaters. This assortment gives you three each of sizes 14, 16 and 18 with silver beads. Try it as the second fly when a plain black midge isn't getting looks.
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Low, clear water is a lesson, not a lost day. South Platte guide Pat Dorsey, on Guided Episode 22 with former FFIP host Greg, made the case that waiting for perfect conditions means you rarely fish. In low, clear flows he goes smaller on flies and tippet, wears drab clothing, wades quietly and treats every cast as the one that counts. That is exactly the situation tiny tailwater nymph patterns are built for.
What Are the Best Tailwater Nymph Patterns Beyond Midges?
Once water warms in spring and fall, Baetis nymphs get active, and scuds and sowbugs are on the menu all year in rivers with lots of weed and aquatic vegetation. These three patterns cover that middle ground.
Barr's Baetis Emerger BWO, Size 18
John Barr's emerger imitates a Baetis nymph working its way to the surface, and it shines on overcast spring and fall days when blue-winged olives start popping. Let the drift swing up at the end, because that rising motion is when trout hit it.
$16.95 Shop Now
Bead Head Flashback Pheasant Tail, Size 18
Frank Sawyer's Pheasant Tail is the classic small mayfly nymph, and the flashback version adds a strip of pearl over the wing case that catches light in clear water. Size 18 matches the Baetis and small mayfly nymphs in most tailwaters.
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Beaded Shrimp Scud Assortment, Size 12
Scuds are small freshwater crustaceans, and rivers like the Bighorn and Lees Ferry are loaded with them. This assortment gives you three each of olive, orange and pink scuds in size 12 with a center bead. Size 12 is the big end of the scud range, so it makes a great lead fly that pulls a tiny midge down behind it.
$21.95 Shop Now
Which Attractor Nymphs Work on Tailwaters?
Attractors are the flies that get a trout's attention when flows change, the water colors up, or the fish are spread out. They also double as heavy lead flies for a smaller natural behind them.
San Juan Worm, Bead Head Red V-Rib, Size 10
The San Juan Worm is named for the New Mexico tailwater where it earned its reputation, and aquatic worms get knocked loose every time the dam bumps the flows. This six-pack of red V-Rib worms on size 10 hooks with a bead makes a great lead fly.
$14.95 Shop Now
Bead Head Oregon Cheese Egg, Size 16
Tailwater browns spawn in fall and rainbows in late winter and spring, and trout downstream key on the drifting eggs. The Oregon Cheese Egg is a small, natural-colored egg on a stout hook with a gold bead, and size 16 keeps it believable to wary fish. Fish it as your lead fly. And please, give the spawners on their redds a wide berth: fish the deeper runs below them, not the fish on the gravel.
$15.95 Shop Now
Black Tungsten Perdigon Jig, Size 18
Perdigons are slim Spanish competition nymphs with a slick, coated body and a tungsten bead, so they cut through current fast. This size 18 black Perdigon rides hook point up on a jig hook, which means fewer snags in rocky tailwater riffles. It's a natural for tight-line and euro rigs.
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How Do You Rig Tailwater Nymph Patterns?
Rigging matters as much as the fly. Most tailwater trout feed close to the bottom, and small flies don't sink well on their own. Here's the setup I'd start with:
- Two flies, big to small. Put the heavier fly up top (a scud, worm, egg or Perdigon) and the smaller midge or Baetis 12 to 18 inches below it.
- Light fluorocarbon. 5X to the lead fly and 6X or 7X to the point fly. Thinner tippet sinks faster and drifts more naturally.
- Add weight before you change flies. If you aren't ticking bottom now and then, add a small split shot above the top fly. Our nymph weight guide covers bead sizes and shot by water type.
- Indicator depth. Start with the indicator at roughly one and a half times the water depth and adjust. The indicator nymphing leader formula I fish is a good template.
- Small indicators, soft sets. Tailwater takes are subtle. Set on any pause, and set with the rod low and downstream so you don't snap 7X.
Pick up fluorocarbon tippet and leaders in our lines, leaders and tippet collection, and if you're planning a trip to Pat Dorsey's home water, our Colorado fly fishing page has seasons and access details.
Colorado tailwater guide Pat Dorsey joined former FFIP host Greg on Guided Episode 22 to talk about the South Platte, Cheesman Canyon and the leader setup he uses for spooky tailwater trout. Episode page.
Frequently Asked Questions
What size nymphs work best on tailwaters?
Most tailwater nymph patterns work best in sizes 16 to 22, with midges often going to 22 or 24 in winter and low water. Larger flies such as size 10 to 12 worms, scuds and eggs are best used as the lead fly in a two-fly rig.
What is the best single fly for tailwater trout?
If you only carry one fly for tailwater trout, make it a black Zebra Midge in sizes 16 to 20. Midges live in nearly every tailwater all year, and the Zebra Midge sinks well and imitates both larvae and pupae.
What tippet should I use for tailwater nymphing?
Use 5X fluorocarbon to the lead fly and 6X or 7X to the smaller point fly on most tailwaters. Fluorocarbon sinks faster than nylon and is harder for trout to see in clear water.
Do I need sowbug patterns for tailwaters?
Sowbugs matter on certain weedy tailwaters, including the Bighorn and the White River in Arkansas. If you don't have a sowbug pattern, a tan or gray scud in a similar size is a reasonable stand-in.
A good tailwater box is a small one, full of flies you trust and rigged so they reach the bottom. Browse the full FFIP fly selection and stock up on fluorocarbon tippet before your next trip.
Tight lines, everyone!
Stock your tailwater box with the flies above and keep chasing any fish, any time, and anywhere.
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