Griffith's Gnat
The Griffith's Gnat is one of the most versatile and effective midge patterns ever created, and it remains a staple in fly boxes across North America. Designed by George Griffith in the 1960s, this simple yet ingenious pattern imitates a cluster of adult midges trapped in the surface film—a common occurrence during midge hatches when multiple insects become tangled together. What makes the Griffith's Gnat so effective is its dual representation. The peacock herl body provides the dark, segmented appearance of midge bodies, while the grizzly hackle palmered along the entire length creates the illusion of multiple insects clustered together. This hackle also provides crucial flotation, allowing the fly to ride high in the surface tension. When viewed from below, the pattern presents a convincing silhouette of struggling midges—an irresistible target for selective trout. Midges are available to trout year-round, but they become especially important during winter months when other aquatic insects are dormant. On spring creeks, tailwaters, and stillwaters, midge hatches can occur daily regardless of weather conditions. The Griffith's Gnat excels in these situations, particularly when fish are keying on clusters rather than individual insects. Size selection is critical—match the natural midges as closely as possible, which often means fishing sizes 20-24. The pattern is equally effective on moving water and stillwater. On rivers and streams, dead-drift the Griffith's Gnat through feeding lanes and along current seams. In lakes and ponds, allow it to sit motionless in the surface film, occasionally giving it a subtle twitch to imitate struggling insects. During heavy midge emergences, when trout become hyper-selective, the Griffith's Gnat often outperforms more complex patterns simply because it presents the clustered appearance fish are targeting. One of the pattern's greatest strengths is its versatility across seasons and water types. It works equally well on freestone streams, spring creeks, tailwaters, alpine lakes, and lowland reservoirs. The simple construction makes it easy to tie in large quantities, which is fortunate because these small flies are easily lost to fish, rocks, and overhanging vegetation. Many anglers tie Griffith's Gnats in various sizes and keep them readily accessible throughout the season.
Pattern Details
- Type
- Dry Fly
- Seasons
- spring, summer, fall, winter
- Hook Sizes
- #18-24
- Hook Type
- Standard dry fly hook
- Tying Difficulty
- Beginner
- Imitates
- Midge cluster/adult midges
Recipe & Materials
- Hook
- TMC 100 or equivalent, sizes 18-24
- Thread
- 8/0 black
- Body
- Peacock herl
- Hackle
- Grizzly, palmered
Technique & Presentation
The Griffith's Gnat is an excellent pattern for beginning tiers to master palmering technique. Start by wrapping 2-3 strands of peacock herl forward to create a full, segmented body. The key to durability is counter-wrapping fine wire or thread over the herl to prevent it from unraveling when fish strike.
When palmering the grizzly hackle, use a feather sized appropriately for the hook—typically one size smaller than you'd use for a standard dry fly hackle. Tie in the hackle by its tip at the rear of the hook, then palmer it forward in evenly-spaced wraps. Each wrap should expose the peacock herl beneath while creating the impression of multiple legs. Secure the hackle at the head and trim the excess.
For added durability on small sizes, some tiers use a thread head rather than attempting to whip finish around the delicate hackle. Flotation can be improved by applying a small amount of dry fly floatant to the hackle before fishing. When fishing, present the Griffith's Gnat with a dead drift, allowing it to ride naturally in the current. On stillwater, let it sit motionless in the surface film, as midges often cluster together without movement. The pattern is most effective when fished on fine tippet—5X to 7X—to avoid spooking selective trout during midge hatches.
History & Origin
George Griffith created this pattern in the 1960s while fishing the lakes and streams of California. Griffith was an accomplished fly tier and angler who recognized that trout often fed on clusters of midges rather than individual insects. His elegant solution was to create a pattern that suggested multiple insects with minimal materials—peacock herl for bodies and palmered grizzly hackle for the cluster effect.
The pattern gained widespread recognition after being featured in fly fishing publications during the 1970s and quickly became a standard pattern in the western United States. Its effectiveness during winter midge hatches on tailwaters made it particularly popular among year-round anglers. Today, the Griffith's Gnat is recognized worldwide as one of the most effective midge patterns ever created, and it appears in virtually every comprehensive fly selection. The pattern's simple design and proven effectiveness have ensured its place in fly fishing history for over six decades.
Where to Fish This Fly
Colorado River at Lees Ferry
Northern Arizona / Coconino County
South Platte River
Front Range / South Park
Frying Pan River
Roaring Fork Valley / Central Mountains
Henry's Fork
Eastern Idaho
Silver Creek
Central Idaho / Sun Valley
Madison River
Southwest Montana
Gallatin River
Southwest Montana
Yellowstone River
South Central Montana
Missouri River
Central Montana
Bighorn River
Southeast Montana
Davidson River
Western North Carolina / Pisgah National Forest
Watauga River
Northwestern North Carolina / Watauga County
Androscoggin River
Northern White Mountains / Coos County
Ammonoosuc River
White Mountains / Grafton County
Ruby Mountains / Lamoille Creek
Northern Nevada / Elko County / Ruby Mountains
Yakima River
Central Washington
North Platte River
Central Wyoming
Bighorn River (Wyoming)
North Central Wyoming
San Juan River
Northwestern New Mexico / San Juan County
Crooked River
Central Oregon
Big Spring Creek
South Central Pennsylvania / Cumberland County
Rocky Ford Creek
Central Washington, Grant County
Related Dry Fly Patterns
Parachute Adams
The most versatile dry fly ever created. The Parachute Adams imitates a wide range of mayflies and serves as an effective searching pattern when no specific hatch is occurring. The white parachute post makes it easy to track on the water. Originally tied with conventional upright wings, the parachute version wraps the hackle horizontally around the post, allowing the fly to land flush on the surface with a more realistic silhouette. This low-riding profile is why many experienced anglers prefer it over the standard Adams. The mixed brown and grizzly hackle suggests the mottled coloring of countless mayfly species, from tiny Baetis to larger Callibaetis. On Montana waters, the Parachute Adams is the quintessential searching pattern. When you arrive at the river and nothing is hatching, tie on a Parachute Adams in size #14 or #16 and start prospecting. During active hatches, sizing down to match the naturals makes this fly deadly. It works on every Montana river from the riffles of the Madison to the spring creek-like waters of the Missouri below Holter Dam.
Elk Hair Caddis
Al Troth's iconic caddis imitation is a must-have on every Montana river. The elk hair wing provides excellent flotation, and the pattern effectively matches adult caddisflies throughout the season. Dead-drift, skate, or twitch it; all methods produce fish. The Elk Hair Caddis is one of those rare patterns that works from the moment caddisflies start appearing in spring through the last hatches of fall. The tent-shaped elk hair wing perfectly mimics the profile of a resting adult caddis, while the palmered hackle gives the fly exceptional buoyancy and creates the impression of legs touching the surface. Its durability is legendary; a well-tied Elk Hair Caddis can take dozens of fish before needing replacement. In Montana, caddis hatches are prolific on every major river. Mother's Day caddis hatches on the Yellowstone in late April and May are among the most anticipated events of the season. The Elk Hair Caddis is equally effective on the rock gardens of the Gallatin, the braided channels of the upper Madison, and the tailwater sections of the Missouri. Vary the body color between tan, olive, and green to match local populations.
Stimulator
An outstanding attractor dry fly and stonefly imitation. The Stimulator excels as a top fly in a dry-dropper rig. Larger sizes (#6-8) match salmonflies and golden stones, while smaller sizes (#12-14) suggest various stoneflies and caddis. The Stimulator's genius lies in its buoyancy and suggestive profile. The combination of a heavily palmered hackle, elk hair wing, and robust body allows it to ride high on turbulent water where lesser flies would drown. The swept-back wing silhouette works as both a stonefly and large caddis imitation, making it effective even when no specific insect is hatching. Trout see the Stimulator and recognize it as a substantial, calorie-rich meal worth rising for. In Montana, the Stimulator truly shines during stonefly season on the Madison, Yellowstone, and Gallatin rivers. Tie on a size #6 orange Stimulator during the salmonfly hatch in late June and fish it tight to the banks. As summer progresses, switch to smaller sizes in yellow for golden stones. The Stimulator also serves as an excellent indicator fly for a heavy nymph dropper, especially when wading pocket water and riffles where it can be challenging to track a strike indicator.
Chubby Chernobyl
A modern foam attractor pattern that has become a Montana staple. Virtually unsinkable, the Chubby floats heavy nymph droppers and draws aggressive strikes from trout looking for a large, easy meal. Available in numerous colors. The Chubby Chernobyl represents the evolution of the foam hopper and stonefly genre. Its layered foam body creates a nearly indestructible fly that requires no floatant and rides high on even the roughest water. The rubber legs provide enticing movement, and the flash wing catches light in a way that grabs attention from trout holding deep. Whether tied in tan, purple, pink, or any other color, the Chubby simply produces fish. Montana guides have embraced the Chubby Chernobyl as their go-to dry-dropper indicator fly, and for good reason. It supports one or even two heavy nymphs without sinking, it is visible at long distances, and trout eat it with startling aggression. On the Madison, Yellowstone, and Gallatin rivers, more fish are likely caught with a Chubby on top than any other dry fly. Its effectiveness extends from early July through October, covering the heart of Montana's fishing season.
Purple Haze
A Montana-born variation of the Parachute Adams with purple dubbing. Created in the Gallatin Valley, this pattern has become a regional favorite that outperforms the standard Adams on many days, particularly during BWO and PMD hatches. The Purple Haze takes the proven Parachute Adams template and adds a subtle twist: a body of purple dubbing that seems to trigger something in trout that the standard gray does not. While purists may argue the color is unnatural, the results speak for themselves. Montana anglers have reported for years that the Purple Haze consistently outfishes the standard Adams, particularly on rivers that receive heavy fishing pressure. Theories about why the purple works vary. Some believe that the color more accurately represents the UV spectrum reflected by natural mayflies. Others suggest that the slightly different hue simply stands out enough on pressured water to be noticed without being refused. Whatever the reason, the Purple Haze has earned its place in the top tier of Montana dry flies. It is especially effective on the Gallatin, Madison, and Yellowstone rivers from late spring through early fall.
X-Caddis
Craig Mathews' brilliant caddis emerger pattern sits in the surface film, imitating a caddis struggling to break through the meniscus. Deadly during caddis hatches when fish refuse higher-riding patterns. The trailing shuck is key to its effectiveness. The X-Caddis fills a critical gap in the caddis life cycle that most fly boxes lack. While traditional dry flies like the Elk Hair Caddis ride high on the surface, the X-Caddis sits flush in the film with its body partially submerged and a trailing Z-lon shuck extending behind. This precisely imitates the moment when a caddis pupa breaks through the surface and begins to shed its pupal shuck, the most vulnerable stage for the insect and the moment when trout feed with the least caution. On Montana's caddis-rich rivers, the X-Caddis can make the difference between a frustrating day of refusals and a banner day of steady action. When you see trout rising during a caddis hatch but refusing your Elk Hair Caddis, the X-Caddis is the answer. It is particularly effective on the Yellowstone during the Mother's Day caddis hatch, on the Madison during summer evening hatches, and anywhere trout have become educated to conventional caddis patterns.