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.
Pattern Details
- Type
- Dry Fly
- Seasons
- spring, summer
- Hook Sizes
- #14-18
- Hook Type
- Standard dry fly hook or light-wire curved hook
- Tying Difficulty
- Beginner
- Imitates
- Emerging caddisflies (Hydropsyche, Brachycentrus, and other Trichoptera)
Recipe & Materials
- Hook
- TMC 100 or TMC 2487, sizes 14-18Shop
- Thread
- 8/0 olive or tan
- Trailing Shuck
- Amber or clear Z-lon
- Body
- Olive, tan, or green dubbing (natural or synthetic)
- Wing
- Natural deer hair, sparse, tent-style
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Technique & Presentation
Fish the X-Caddis on a dead drift in the surface film. Unlike the Elk Hair Caddis, this pattern should not be dressed with floatant on the body; you want it to ride low. Apply a small amount of floatant only to the deer hair wing to keep it visible while allowing the body and shuck to penetrate the surface.
Present the fly upstream of rising trout during a caddis hatch, focusing on the same feeding lanes where you see refusals to higher-riding patterns. The X-Caddis often draws confident takes where other caddis patterns produce short rises or splashy refusals. The trailing Z-lon shuck is the trigger; trout recognize it as a caddis that cannot escape and commit to the take.
The X-Caddis can also be effective swung on a downstream presentation to imitate a caddis dragging its shuck across the surface. This technique works especially well in the evening when caddis are active and trout are feeding aggressively. Use 5X tippet in most situations.
History & Origin
The X-Caddis was created by Craig Mathews, the legendary fly fishing innovator and founder of Blue Ribbon Flies in West Yellowstone, Montana. Mathews developed the pattern in the late 1980s while guiding on the rivers around Yellowstone National Park, where he observed trout consistently refusing traditional adult caddis patterns during heavy hatches.
Mathews' key insight was that trout were feeding selectively on caddis emergers stuck in the surface film, not on fully emerged adults. By eliminating the hackle and adding a trailing Z-lon shuck, he created a pattern that sat in the film rather than on top of it. The X-Caddis was published in Mathews' and John Juracek's influential book 'Fishing Yellowstone Hatches' and has since become one of the most important caddis patterns in the fly fishing world.
Where to Fish This Fly
Madison River
Southwest Montana
When fish refuse the EHC
Henry's Fork
Eastern Idaho
X-Caddis for evening caddis hatches throughout the river
Deschutes River
Central Oregon
The single most important fly on the Deschutes, essential during evening caddis hatches
McKenzie River
Willamette Valley / Cascades
Excellent caddis emerger for selective fish. Flush in the film.
Owyhee River
Southeastern Oregon
Caddis dry. Skitter through riffles for explosive strikes.
Methow River
North Central Washington, Okanogan County
X-Caddis when trout become selective to emergers during caddis hatch
Klickitat River
South Central Washington, Klickitat County
October Caddis emerger pattern
Upper Kennebec River
Western Maine / Somerset County
X-Caddis in sizes 14-16 during prolific evening caddis emergences in the gorge.
Rapid River
Western Maine / Oxford County
X-Caddis in sizes 14-16 during summer caddis emergences.
Grand Lake Stream
Downeast Maine / Washington County
X-Caddis in sizes 14-16 during summer caddis emergences for salmon and brook trout.
East Outlet of the Kennebec River
North-Central Maine / Piscataquis County
X-Caddis in sizes 14-16 during prolific caddis emergences from the cold lake-fed water.
Saco River
Mount Washington Valley / Carroll County
X-Caddis for prolific summer caddis hatches. Evening emergences. Size 14-18.
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.
PMD Comparadun
A flush-floating mayfly imitation that excels during Pale Morning Dun hatches. The deer hair wing creates a realistic silhouette, and the pattern sits low in the film like a natural dun. Essential during PMD hatches on the Missouri and Madison. The Comparadun design is one of the most elegant solutions in dry fly fishing. By using a fan-shaped deer hair wing instead of traditional hackle, the fly sits directly on the water surface with its body in the film. This creates a silhouette that is nearly indistinguishable from a natural mayfly dun when viewed from below, exactly the perspective that matters to a feeding trout. The PMD version, tied in pale yellow and olive, is one of the most important patterns for Montana's prolific Pale Morning Dun hatches. PMD hatches on Montana's premier rivers are events that every serious fly angler should experience. On the Missouri River below Holter Dam, PMD hatches from late June through August produce some of the best dry fly fishing in North America. The Madison River's upper sections also host excellent PMD activity. During these hatches, trout can become excruciatingly selective, and the low-riding Comparadun is often the pattern that cracks the code when parachute and traditional dun patterns fail.