The Caddis: An Introduction

Known for their tent-like wings, several species of caddis are prevalent throughout Montana’s world-renowned wild trout fisheries. From the Mother’s Day caddis hatch of spring to the October caddis of fall, their presence is a constant during the Montana fly fishing season.

Caddis undergo complete metamorphosis during their lifecycle with the pupa and adult stages being the most significant to anglers fishing a hatch. The pupa ascend through the water column to emerge as adults at the surface. During peak activity, trout feed on both caddis pupa and adults with aggression.

Montana hosts over 20 caddisfly species, each with unique characteristics. The most common include the Mother’s Day Caddis (Brachycentrus occidentalis), the Hydropsyche, and the Glossosoma. These species hatch across the legendary Montana rivers, with activity peaking in spring and early summer. Their abundance and prolific hatches make caddis an entomological cornerstone of fly fishing in Montana.

The 5 Best Montana Rivers for the Caddis Hatch

1. Madison River

The Madison River is legendary for its summertime caddis hatches. They are found throughout the river, with the sections between Quake Lake and Lyon’s Bridge having the most consistent summer emergences. Evening hatches bring explosive surface action as trout ambush emerging caddis in the fast pocket water and riffles.

2. Yellowstone River

Known for its wild trout and iconic beauty, the Yellowstone River offers world-class dry fly fishing during caddis hatches in spring and summer. The Paradise Valley sections are particularly productive with evening caddis hatches. The Mother’s Day Caddis hatch here is among the best in the world and signals the start of the Montana fly fishing season for many anglers.

3. Big Hole River

The Big Hole River's diverse water types and prolific caddis hatches make it a prime destination for anglers who prefer dry fly fishing over nymphs or streamers. Sections near Wise River and Divide are hotspots for summertime evening hatches. Look for trout rising in slower pools, pocket water, and along bankside seams during the emergence and egg-laying flights.

4. Missouri River

Below Holter Dam, the Missouri River is renowned for its prolific caddis hatches, boasting some of the best dry fly fishing in Montana. Trout can be highly selective in this tailwater fishery, particularly during evening emergence. Focus on seams and back channels near Craig, Montana, where trout often key in on caddis pupae and adults.

5. Gallatin River

The fast currents and clear waters of the Gallatin River are home to a diverse and robust population of caddis and other aquatic insects. The Gallatin Canyon sections near Big Sky offer consistent caddis hatches throughout the summer. Evening dry fly sessions during summertime fall last well past sunset in July and August.

Other Notable Montana Caddis Hatches

The Traveling Sedge is a large type of Caddis known for scurrying across the water to deposit its eggs. Anglers fishing Georgetown Lake near Anaconda, MT. in July and August elicit explosive strikes from cruising trout by fast-stripping large caddis dries across their path with a "skating" action. A size 8 Goddard Caddis or a size 10 Water Walker in a light tan are a couple of standard flies to have in the fly box.

Swarms of black caddis join the myriad other species of hatching insects each summer on Montana’s Bighorn River. Selectively feeding trout can be found rising along the inside edges of a soft, riffle seam to black caddis adults during the peak of midsummer hatches. Although the water might be covered in PMD’s, these highly selective – and often very large – Montana trout sometimes just prefer the black caddis.

October Caddis are the last of the seasons' caddis hatches of note for anglers fishing in Montana. Although they are found throughout the state, they are of more significance on the rivers near Missoula, like the Blackfoot, Bitterroot, and Clark Fork. Their nymphs are of more significance to trout feeding behavior than the dries but don’t hesitate to try blind casting a large, orange-bodied dry fly when you see them over the water.

Top 10 Flies for Fly Fishing in Montana During a Caddis Hatch

Caddis Dry Flies

1. Elk Hair Caddis (Size 12-16) - A versatile pattern that imitates adult caddisflies. Its buoyancy and lifelike silhouette make it a staple for dry fly fishing. Tan, peacock, and olive colorways are essential when flyfishing Montana during the summertime.

2. X-Caddis (Size 14-16) - Featuring a trailing shuck, this Craig Matthews pattern mimics emerging caddis and is a time-tested Montana fishing guide favorite.

3. Bloom’s Parachute Caddis (Size 14-16) - The hi-viz parachute design provides excellent visibility while the body sits low in the surface film. This is an effective caddis dry during caddis hatches everywhere, but it is particularly effective on flat water rivers like the Missouri and Bighorn Rivers.

4. Goddard Caddis (Size 12-16) - A high-floating pattern with a spun deer body is ideal for fly fishing fast water rivers like the upper Madison and Gallatin. It’s a good idea to always have a few of these in the fly box to try over selective trout that refuse other imitations.

5. Cornfed Caddis (Sizes 14-18) – This CDC-bodied dry fly sits low in the water for a realistic presentation during calm evenings when fly fishing slick water tailouts and seams.

Top Caddis Emerger Patterns

6. LaFontaine’s Sparkle Pupa - Mimics the gas bubble of emerging caddis pupae, making it deadly during the pre-hatch phase. Gary Lafontaine literally wrote the book on Caddis, and this time-tested imitation is as effective today as ever.

7. Iris Caddis (Sizes 14-16) - This unusual caddis imitation relies on simplicity to create a highly effective utilitarian fly that is easy to tie. Another Craig Matthews original, the Iris Caddis origins can be attributed to the cracking of the code of Madison River fly fishing.

8. Peacock Soft Hackle (Sizes 14-16) – Simple soft hackle flies work well whether they are fished alone or as a dropper behind the anglers pick of caddis dry fly imitations. The peacock bodied version with Hungarian Partridge soft hackle is a must have during the Mother’s Day Caddis hatch.

Best Caddis Nymph Patterns

9. Mangy Caddis (Size 14-16) – This simple tie has a blend of flash and movement to its dubbed body that works year-round as a caddis pupa or larva imitation on Montana rivers.

10. Tung Dart (Sizes 14-18) - The tungsten bead gets this micro soft hackle fly down to deep trout feeding near the river’s bottom during the hours before the hatch begins.

Angling Tips for Fly Fishing a Montana Caddis Hatch

Best Time of Year - The prime caddisfly season runs from May through July, with sporadic hatches in late summer. The Mother’s Day Caddis hatch in late April and early May offers up some of the best Montana dry fly fishing of the year.

Presentation Technique - Use a drag-free drift for dry flies and emergers. For pupae patterns, swing them down and across the current so that the fly stays just below the surface to elicit explosive strikes.

Rod and Fly Line Recommendation – Montana fishing guides prefer modern fly rods with a fast action for maximum versatility in the varied weather conditions of the northern Rockies. The G. Loomis Asquith, Hardy Ultralite X, and St. Croix Evos are a few of our top picks in the 9-foot 5-weight configuration. Pair any of these with the Elite Rio Gold fly line for peak performance, whether fishing dries or wet flies during a caddis hatch.

Best Time of Day - Evening hatches bring the most surface activity during the midsummer months, especially during calm weather. On warm, overcast days, trout feed on hatching caddis throughout the day.

Experience Montana Fly Fishing with Fins and Feathers

Fins and Feathers Guide Service has been outfitting guided fly fishing in Montana for over two decades. Caddis hatches occur daily during the prime Montana fly fishing season between May and September on the Big Sky State’s many storied trout waters. Their emergences keep trout active throughout the season, providing dry fly fishing opportunities almost every day of the season.

Contact us for help planning your Montana fly-fishing vacation around the famed Mother’s Day Caddis hatch for a unique dry fly fishing experience. Reservations can be placed online, via e-mail, or by calling us at 1-406-469-5019.