The Mothers day caddis is the first significant caddis hatch in the west and can bring some of the best fishing of the year with it. Bozeman fly fishers are most likely to fish this hatch on the Yellowstone or Lower Madison but it occurs to one degree or another on almost all our area rivers. Also known as Brachycentrus and Grannom, the Mother’s day caddis is a relatively large, (14 to 16) dark bug that usually comes off in the afternoon. The hatch is usually going by early May although the fact that it comes at such a transitional time of year makes the Mother’s Day Caddis one of the most difficult hatches of the year to predict. Air temperature, water temperature, water clarity, light conditions, and section of the river you’re fishing all play a role in how thick the hatch is. If conditions are right, however, the fishing can be truly epic and be the type of event that makes anglers wonder where all those fish go the rest of the year.
Standard western fishing tackle is usually perfect for fishing the Mother’s Day Hatch. A 9 foot, 5 weight fly rod with a 9 foot 4 or 5x leader is usually fine for this fishing. A lot of folks like to fish a 4 weight for the dries but remember that spring time in the west means a good chance of wind. If the wind is heavy, you might even want to fish a 6 weight, especially if you’re nymphing ahead of the hatch. Be sure and carry a quality dry fly floatant like Gink or Aquel to use before fishing, along with a good desiccant powder like Loon’s Top Ride, because if the fishing gets fast, your flies will quickly become waterlogged.
Fly choice depends largely on the stage of the hatch that you’re fishing. Early in the day, before the adult caddis are on the water and the fish are rising, a variety of Larval and pupil patterns can be successfully for indicator nymphing. We like Bead Head Caddis Larva, Z-Wing Caddis, Deep Sparkle Pupa’s, and Bead Head Mother’s Day Caddis Pupa’s. The good old Prince nymph also shines this time of year and is a great fly to fish above one of the more realistic flies and below a thingamabobber. In the afternoon when the hatch progresses and fish begin to show themselves on the surface, we’ll tie on a big caddis dry fly, like a Peacock Elk Hair Caddis, Bloom’s Para Caddis, or Hot Wing Elk Hair caddis, and drop one of the pup patterns listed above below it. Another favorite for a dropper is the standard Mother’s Day Pupa. As the hatch gets heavier, competition from the naturals makes a big bright attractor fly a great choice. Lime Trude’s, Royal Wulff’s, Bugmeisters, and Neversink Trude’s are all easier for both the fish and the fisherman to pick out of the incredible mass of caddis that is common for this hatch.
Keep in mind that this time of year also sees hatches of western March Browns and Baetis so keep a handful of patterns that represent both of those patterns, especially on cloudy days that can slow up the caddis emergence. Cold and overcast days in the spring will usually provide better mayfly hatches that caddis. A plus side to the occasional cold day that puts of the caddis is that it usually helps keep the river from blowing out. We are almost always on the cusp of spring run off during the Mother’s Day Hatch, and it’s usually spring run off that puts an end to the hatch. This is especially true on the Yellowstone. Cooler weather can also keep the hatch more “fishable”. When the caddis hatch is in full force, competition from the naturals makes it almost impossible for fish to find your fly. Also at some point the fish just seemed gorged and will let mats of caddis pass over head unmolested. At these time’s, the river can suddenly seem dead, like someone threw of the switch for the fish to feed. When this happens it’s best to just move along and try to find feeding fish somewhere else.
Transportation becomes and important question when fishing the Mother’s Day hatch. Both float and wade fishing have advantages and disadvantages. Floating allows you to cover a great deal of river and have a better chance of hitting the sweet spot where the bugs have the fish up but aren’t too heavy to fish. Floating is also great on days when the bugs haven’t gotten too thick anywhere and fish can be found sporadically rising throughout a given stretch of river. Floating anglers can usually find a lot more fish up on these types of days than a wade fisherman would, simply because they can cover so much more water. The downside to floating is that once anglers find the best part of the hatch, they may have to eventually have to float past them. It’s easier for wade fisherman to tee off on the fish once they find them. When the fishing slows, anglers can drive upstream, the same direction the hatch is moving to look for more fish. Wade fisherman also have the luxury of thoroughly working rising fish instead of making one shot at them as they drift past. This can be a big help when the hatch is heavy and it may take several drifts for the fish to see your fly. Of course, drifting anglers can always anchor up once they find rising fish, but eventually they have to get back to the boat ramp.
Hitting the Mother’s Day hatch can be some of the best dry fly fishing you’ll ever see. It can be a little tricky to hit right but you can hedge your bets buy using a quality guide. They’re on the water almost every day that time of year and know better than anyone where the bugs are and what’s up with river conditions. Out of state anglers should give hiring a guide especially strong consideration. The hundreds of miles of rivers in our area can be overwhelming, intimidating, and confusing to visitors. Trying to hit a specific event like the Mother’s Day Caddis only makes it tougher. Without a doubt, the risk is worth the reward. There’s no site out here that quite compares to looking up usually banks of the Yellowstone and seeing thousands of fish up eating caddis. Seeing them eat your fly over and over throughout the day is even better.