April 22, 2022
This article originally appeared in the July 2006 issue of Fly Fisherman. Click here to see a PDF of the print article of "Mother's Day Caddis".
I remember being half out of my wits in Montana's Gallatin Valley when I decided to quit my job and go fishing. I was getting a lot of time on the water, but there were some important events I'd be missing, including an early season Rocky Mountain caddis blitz that seemed beyond accurate description. When trout bums boasted of the hatch, the superlatives flowed from their mouths.
"Absolutely the best dry-fly fishing of the year," one confidant said.
"Pure carnage," another promised. "Billions of bugs stacked one atop the other, fish gorging, and hardly anyone on the water."
One early May afternoon I was on a stool at Stacy's Bar in Gallatin Gateway, Montana, trying to forget about working, when I spied a rail-thin guide sitting across the horseshoe bar. This guy never looked good, but now he appeared totally spent, with purple lines under his eyes and greasy hair foiling from a sweat-soaked and fly-laden ball cap.
I wanted to ask how long he'd survived on tomato soup and Budweiser, but instead I managed, "Is the caddis hatch coming off?"
He lifted a whiskey and said: "Look at me. l've fished until after dark for a week straight. My clients are having a heyday and I'm getting run ragged. Be on the Madison tomorrow at 4pm."
I left a tip on the counter, a two-beer credit for the guide, and headed to my tying table. The following day, flush with fish fever, I quit my job and waded into a caddisfly frenzy on the Madison River. Insects clung to my waders, crawled in and around my ears, wiggled behind my sunglasses, and slithered down the nape of my neck. Wind gusts blew the caddis against my waders with a sound reminiscent of hard rain hitting pavement.
My view of the far bank was partially blurred by the swarm, and mats of caddis, which looked like chunks of carpet, floating downstream. I inhaled through my nostrils to avoid choking, and watched fish rising with enthusiasm, gorging on the largest flies they had seen since the previous summer. I twisted an Emergent Sparkle Pupa to the end of a 5X tippet and decided that all the stories attached to the Mother's Day caddis hatch were as accurate as they could he. Never had I seen such a hatch.
The caddis I saw on the Madison are Brachycentrus occidentalis, sometimes called early Grannom caddis, but also known as Mother's Day caddis. The pre-runoff Mother's Day caddis hatch is a well-known event in the trout-rich states of Montana and Colorado, but it also occurs on Washington's Yakima River as well as on many rivers in Idaho, Wyoming, Oregon, and California.
Although called the Mother's Day hatch, the hatch begins in late April on most streams, often just before runoff, and lasts a few weeks. On lower elevation rivers where the hatch starts early–such as the Yellowstone near Livingston, Montana,or the Colorado River near Glenwood Springs, Colorado–the hatch is usually winding down by Mother's Day. In higher elevation streams the hatch is sometimes true to its name and is still going strong on Mother's Day and through the middle of May.
In the Rockies, look for intense Mother's Day caddis hatches on the Madison, Yellowstone, Big Hole, Beaverhead, Ruby, Rio Grande, Arkansas, Colorado, Animas, and Roaring Fork rivers. The hatch may not be as dense on some of these waters, but Brachycentrus occidentalis is an important caddis species on almost every trout stream in the West and it pays to carry caddis patterns anywhere you fish during April and May.
Because the hatch arrives early in the season–before tourist season but also before runoff–it can be hit-or miss for dry-fly anglers. To find the best fishing, plan your trip to coincide with the warming trends of spring. The caddis hatch is at least partly triggered by warming water temperatures, but if the weather becomes too warm the rivers quickly rise with spring runoff and become tendrils of mud.
Local anglers who fish during optimum conditions know the hatch is not only viable, it's the highlight of the pre-runoff season. Traveling anglers, however, face the fickle weather of springtime in the Rockies and must accept what comes their way. You can plan your trip to find heavy caddis hatches easily enough but water conditions are less predictable. Rivers can blow out overnight during spring due to rain or snowmelt but if you are flexible, you can sometimes still find a caddis hatch, and decent water conditions, farther upstream or in a nearby watershed.
For those who hit it just right, the spring caddis blitz is a memorable experience with trout that are totally committed to deliberate surface feeding. On good days, trout numbers mount as the teeth of multiple fish shred Trudes, Elk-hairs, and Sparkle Pupas.
Flies and Tactics for Mother's Day Caddis
Adult Brachycentrus caddis have a black head and a dark olive or black body. When the adults first emerge, their wings are dark gray to black but the wings become semitranslucent, tan, or cream-colored by the time they are ready to mate. They are closely matched with a #14-16 hook, but larger flies often catch more fish.
Trout feed on all phases of the Mother's Day caddis hatch–drifting larvae, swimming pupae, emerging adults, and egg-laying females. However, during the hatch and subsequent egglaying flight, most fish eagerly pound nothing more technical than adult imitations and general attractors.
The Mother's Day hatch progresses as most caddis hatches do, with the larval insect transforming to a pupa that drifts slowly to the surface where, eventually, it emerges as an adult. After mating, adult females return to the river and deposit their egg sacs in one of two ways-by dapping their abdomens on the surface or crawling underwater to release the eggs.
The hatch typically begins between 1 and 4 PM. and lasts until dark, which offers a nice half-day of fishing or an after-work option for local anglers. Attractor dry flies, including Chuck Stranahan's Peacock Trude and Caddis Variant, Sanchez's Everything Emerger, Hans Weilenmann's CDC & Elk, the Parachute Caddis, and Al Troth's Elk-hair Caddis (with a peacock body), draw ample takes.This is the simple beauty of this early caddis hatch-a handful of flies and hungry fish make this event less technical than summer caddis hatches, which can be perplexing. Finding the water in prime condition is the most important element.
Even though the fishing can be relatively easy, you sometimes find one large trout that forces you to imitate a particular stage of the hatch, and wise anglers carry specific patterns to match both the emerging pupae and egg-laying stages. Early in the hatch, a picky fish is most likely targeting drifting or emerging pupae. In this case, use a tan or green Lafontaine Deep Sparkle Pupa or an Emergent Sparkle Pupa. These patterns, designed and popularized by the late Gary Lafontaine, are killers during this hatch. The Deep Sparkle Pupa mimics a freshly emerged pupa and is most effective dead-drifted near the bottom. The Emergent Sparkle Pupa is best near the surface. Grease the wing with floatant so it rests in the surface film just like a real pupa attempting to break free of its skin. These patterns have Antron yarn bodies that may trap air and reflect light similar to the air bubbles natural pupae carry.
While dead-drifting dry flies during an emergence is usually adequate, twitching and swinging pupae patterns and soft hackles fools fish as well. Caddis pupae emerge slowly, often with pauses and twitches. To mimic those movements, mend your line or periodically lift your rod tip to move the fly slightly during a drift.
To perform the Leisenring Lift, cast your fly upstream of a visible fish, or above where you expect a fish to hold. Follow the drift of a fly with your rod tip until it reaches the trout, and then stop the rod to tighten the line and move the fly toward the surface.
A similar tactic, used by Rene Harrop and described in his book Trout Hunter (Pruett Publishing Company, 2004), suggests casting an emerger downstream, several feet above a feeding trout. When the fly drifts within about a foot of the trout, Harrop lifts the rod tip, raising the fly to the surface. After the fly makes a subtle disturbance, he drops the rod tip and allows the fly to drift naturally, just under the surface film, directly in the trout's feeding lane.·
Another effective but simple technique is to cast a pupa pattern or soft hackle across-stream and allow it to rise through the water column at the end of a drift.
Egg-laying flights typically occur about an hour before dark. Regular attractor dry flies still catch fish during this time, but you may want to mimic a caddis female depositing its eggs or any adult caddis, dead or alive, riding the surface.
A peacock-body Elk-hair Caddis with a green yarn egg sac, fished with twitches or skittered slightly, imitates a female caddis dragging its abdomen while depositing eggs. However, with so many caddis on the water, a moving target is often overlooked in favor of spent caddis dead or dying in the surface film. The peacockbody Elk Hair, the Everything Emerger, and the Spent Sparkle Caddis are fine representations of crippled and spent caddis. Look for trout feeding on spent caddis by watching for slow, subtle rises, rather than the splashy rises and jumps that indicate trout feeding on caddis emergers and skittering egg-layers.
A good pattern to try during egg-laying flights is the Diving Caddis, which represents a female caddisfly that has pierced the surface film and wiggled toward the bottom of the river to release its eggs. The Diving Caddis, like the Emergent Sparkle Pupa, is tied with an Antron wing, which mimics an air bubble that a natural carries to the bottom of a river. When fishing a Diving Caddis, do so with an upstream cast and a dead drift.
According to Lafontaine, author of Caddisflies, whom I interviewed before his death from ALS, the Diving Caddis can be fished before or during the hatch.
"I like to fish the Diving Caddis unweighted," he advised. "I cast upstream and let it dead-drift just under the surface. I use an Elk-hair Caddis or an X-Caddis as the dry-fly indicator, and I'll drop the Diving Caddis about nine inches behind the dry fly."
While many anglers stick to the afternoon and evening hours when pursuing the spring caddis hatch, there is often productive fishing all day for those who don't mind subsurface fishing. Drifting larvae are abundant this time of year and two of the best patterns during non-hatch hours are #12-14 Scott Sanchez's Glass House Caddis or Matt King's Caddis Pupa. These patterns are early-season killers when fished under an indicator and bounced along the bottom in and below riffle areas.
No matter which stage of the hatch you match, or which fly you use, there are a couple of proven spring caddis tactics that put more fish in your net. The most important thing you can do is oversize your fly. The Mother's Day Caddis hatch is a saturation event, and your fly often gets lost in the abundance. To get your fly noticed, use one size larger than the #14-16 naturals. Over sized flies are easier for the trout to find, and are easier for you to see on the water. If the water is dirty, larger flies are also more visible to the trout. When water clarity is poor, concentrate your fishing near the banks where trout take refuge in elevated flows. As flows stabilize and clarity returns, the caddis action is sometimes phenomenal.
During an intense hatch, caddis are on almost every square foot of the surface but they are particularly dense just below riffles. Early in the hatch, this is where the best action is, but as the hatch intensifies it pays to find water with fewer bugs.
Side channels, where the insects are often less abundant, are productive and can harbor large trout looking for shelter from high flows.
Last April, while fishing the Yellow stone's famous afternoon and evening caddis hatch, I found a quarter-mile-long side channel with flat water and rising trout from top to bottom. What caught my eye was the hogs sipping adult caddis just inches from the bank. Deliberately, and with the satisfaction found only in the first dry-fly action of the year, I worked up the bank picking off sippers: first a 19-inch male brown, then a 20-inch female, followed by an 18-inch rainbow. If the fly landed above a fish and drifted into its feeding lane, the trout ate it without hesitation. And they ate like that until after dark, which gave me five hours of angling bliss.
Hiking back to my truck that night, I thought I probably wouldn't have a better day of dry-fly fishing that season. After a long, cold, housebound winter, finding this hatch was like winning the angling lottery.
Fly Recipes for Mother's Day Caddis
Chuck's Peacock Trude
HOOK: #10-16 Targus 5212.
THREAD: Dark olive 6/0.
TAIL: Deer hair.
BODY: Peacock herl wrapped on top of wet head cement for durability.
WING: White calf tail, tied sparse and flared.
HACKLE: Spencer golden ginger and grizzly dyed dark olive.
Emergent Sparkle Pupa (tan)
HOOK: #12-16 Mustad 94840
THREAD: Tan 8/0
UNDERBODY: Olive rabbit fur and olive Sparkle Yarn (50/50 mix) dubbed
OVERBODY: Tan Sparkle Yarn
WING: Deer hair
HEAD: Brown fur dubbing
Chuck's Caddis Variant
HOOK: #12-16 Targus 921.
THREAD: Olive 6/0.
BODY: 50/50 blend of Highlander green and golden olive Anteon dubbing.
WING: Deer hair, short black tips, fine, hock or shoulder trim, dyed to match shade of hackle.
HACKLE: Spencer's caddis dun.
Greg Thomas was Fly Fisherman’s Western Field Editor, the author of many books, and former publisher of Tight Lines.