Fishing the iconic Salmonfly (Pteronarcys californica) hatch on the Fifty-Mile Riffle is an epic experience to say the least. Snow-capped mountains and lush green hillsides frame a robust river flush with the bounty of early season snowmelt. Tremendous browns and rainbows rise eagerly to engulf massive insects from the surface. It’s the stuff of legends.
Though, like many phenomenons, they are all too often elusive. One day you’re a bit too far upstream of the hatch, the next day you’re too far behind it. Sometimes you’re right smack in the middle of the hatch, but the fish have seen too many bugs and reject your fly as if to say “sorry Sucker, better luck next time”.
Every so often, when the stars align, you get to watch in amazement as big trout erupt on your dry fly, and tear upstream in a violent and powerful run. On days like these you can do no wrong, it’s as if every trophy trout in the river has been waiting all year just to eat your fly. Though, sadly, that’s not the norm. The reason those epic days are so special is because they so rarely happen.
I’ve spent many days watching perfect drifts go unrewarded during the Madison’s salmonfly hatch with perfectly presented stonefly imitations. Over the years I’ve been forced to look past the obvious attraction of the Hollywood Hatch, and look deeper for other ways to feed these crafty trout. More times than not, the answer has been with Arctopsyche grandis.
Arctopsyche grandis is a large (size #8-10) chocolate-colored caddis that is conveniently at its peak of activity on the Madison River when salmonflies are hatching.
A. grandis are predominantly nocturnal, but at their peak abundance, the sheer volume of insects provides an ample supply of unlucky individuals who fall or get blown from stream side vegetation into the drift. Just like Salmonflies, Arctopsyche adults can be seen fluttering haphazardly across the surface, especially close to the banks, on windy afternoons.
Conveniently, many of the Madison’s best brown trout occupy those prime lies along the bank, hunting opportunistically for any and all insects that come their way, not just the immense stoneflies.
I generally prefer to present a single dry fly to these sneaky bank feeders. I like a 10-12 foot leader (depending on wind), with a long 2-3 foot tippet section of soft monofilament. When casting from the drift boat, I find a downstream presentation with a reach cast to be the most effective. When wading, I like to approach from below my target, fishing upstream with an elevated pile cast and a slight reach to the bank side.
Dry fly patterns like a size #10 Royal Stimulator, #10 Micro-Chubby, or #10 PMX are all great searching patterns when Arctopsyche are active. All of these flies are also great imitations for the multitude of smaller stoneflies which are present at these times.
When dry fly fishing isn’t producing, often in the week or so leading up to the hatch, larval imitations of A. grandis can be seriously effective. These large larvae are found in size #8-10 on the Madison with a bright olive body and a dark brown head. Nymph patterns like the BSA Beadhead Caddis Pupa, and a Tungsten King Prince are a great choice.
Don’t get me wrong, on days when the infamous fish on the Madison are crushing Salmonfly dries I will cast them until my arm falls off. But when they’re not, you will most likely find me fishing an Arctopsyche imitation….with a bent rod.
So, keep an eye out for these large, chocolate-colored caddis the next time you’re fishing the Madison during stonefly activity, and keep their imitations on deck if you’re watching too many of your own perfect drifts with a Salmonfly go unrewarded.