We are getting near that mystical time of year when both the Yellowstone and Madison rivers see a hatch like no other. The skies grow dark, the surface of the water becomes alive and the trout rise from bank to bank. I am speaking of the Mothers Day Caddis Hatch.
Every year around the first to middle of May when the rivers temperature reaches that magical number of 52 degrees the river comes alive with blanket hatches of brachycentrus occidentalis. Some call it the "floating carpet" or "caddis Blizzard" or many of its other names. It is truly a site to see. The hatch progresses up river much like the salmonfly hatch and speeds up or slows down with the daytime temperatures. This isn't the first hatch of the season but it is an impressive one. It isn't an easy hatch to fish as you are competing with billions of real insects both alive and dead. When the hatch is in full swing the adults are everywhere, in your drinks, tickling your neck and swarming in the bottom of your boat and on your waders. Early in the day we like to use a dry-dropper rig. A bigger than normal royal trude or hi-vis elk hair caddis followed by a sparkle pupa, seridipity, or a peacock soft hackle. When the sun gets lower the surface fishing improves and x-caddis, elk hair caddis's, skittering caddis's, trudes, or any down wing patterns will surfice tied onto a 9 foot 4x leader. I generally use a size or two larger fly than the naturals just to stand out from the crowd and to be able to see my dry fly easier. In summary keep a close eye on water temps as they start to climb. When this hatch starts, be prepared for fishing both dry flies and nymphs to cover all your bases. If you hit this hatch right you will remember it for the rest of your fishing days.