Hopper Fly Fishing Pattern Montana

The Cycle Of Flies

The Missoulian Angler Fly Shop is the oldest fly shop in Missoula, with over 100 years industry experience on staff. We’ve seen a few things in 35 years. This year we’re seeing Schroeder’s Parachute Hopper is hot, like microwave lasagna hot.

We’ve stocked the Parachute Hopper for at least 25 years. We first got it in because it was working so well, and had to have it. Since then, we’ve watched the ebb and flow in sales. It always works to some degree. We’ve watched that fly sell less than 6 dozen a year to being the hottest fly on the river. That’s a big swing, and we’re ready for it!

The swing comes from the trout. Our customers and Missoula’s best fly fishing guides are in daily contact, listening to what they say. This year they say Schroeder’s Hopper. Last year they said the G Kes. If you’re on the water, paying attention, the trout will tell you things about your fly choice as well. The Missoulian Angler will help translate if you’re not hearing what you think you should be!

Hot flies are like the weather. If you want to know about the weather in August, or the hot fly, ask us on September 1! We’ll have a great idea then. But before that, it’s a crap shoot. Of course, we’ve all seen James Bond shoot craps- there is some methodology to placing your bets- but no guarantees. You do the best you can with what you have, and try not to roll too many 7’s!

OMG! The one hit wonders. Can’t keep ‘em in stock for a season, and then two years later 40 dz. are decorating the Dollar Bin. There are some shops that buy flies for their Dollar Bin. Not us! We can fill ours with flies we thought would be hot, or were previously hot, or never got hot. Customers ask all the time, “How did this fly get in here?”, and we’re always forced to answer, “On merit.”

It’s starting again for next season. We buy flies from 9 different venders and keep our local tiers busy tying our custom patterns, and keep looking for more to maintain the best fly selection in Montana. It’s like sending a fat guy to the doughnut shop! Sales reps appear with overflowing boxes of new fly patterns, and we start salivating like Pavlov’s dog. What’s going to be so good we have to have it? Who’s come up with the latest and greatest, that perfect combo of the Purple Haze, Sex Dungeon and Pheasant Tail that’s going to be so hot fish jump in the boat to take it. Take our word for it, they all look good enough to eat! And the cycle continues, but not without consequence.

We only have so many bins in the shop, and get new flies all the time. Like the art collector with no more wall space, where does our new purchase go? What leaves to make space. Sometimes the choice is easy, like the pink and orange wooly bugger. What were we thinking! Sometimes it’s more difficult, like removing the Copper Bob in various colors. Hottest fly in the early 2000’s- it’s lost its mojo. Some customers will be annoyed, finding the old tried and true gone. That’s when we ask you to take some things on a little faith.

We want you coming back. We ‘re don’t sell flies that happen to be in stock, flies that don’t represent your best bet on the water. That’s not how we roll. Missoulian Angler is the oldest fly shop in town for a reason – repeat customers. We’re intense about flies, and when a pattern disappears, it means we’ve found better. This is where trust comes in. We know you’ve been using a pattern for 20 years. It works for you. You trust that pattern. And trust is key! We know the moment you lose faith in a fly, it’s done. It takes a little time to find the trust for a new fly.

A while a go, a customer told us a story. His son in law had given him a new fly- said it worked great. He tied it on and fished it for 10 minutes. Nothing. He lost faith in the new fly, and tied on the trusty Pheasant Tail. 3 ½ hours later he caught a trout. See! It works! It wasn’t till later he saw the humor in that, but it was the old tried and true.

Watch the best guides in Missoula go to work. If nothing is happening, they make something happen. Tried and true, or something new, if one fly isn’t working, they move on! Find the size, find the color. One of the first lessons every angler learns is what good water looks like. Fish are there, and if you haven’t spooked them, they’re eating. If they’re rising, even more so! You need to be able to reach into your box and have something a bit different, a new look if you will. Buy your flies shallow and wide- that means don’t buy 12 Parachute Mahoganies, buy 4 of those, then some cripples, some Comparaduns. You know, the same, but different. Give the trout a bigger selection, and you’ll find their selectivity isn’t as big as issue as it once was.

The Missoulian Angler has the largest fly selection in the city of Missoula and likely Montana. We’re willing to say the biggest fly selection within 200 miles of Missoula! And it’s not just wide, it’s deep. For those who visit the shop, you’ve seen the storage beneath the fly bins. That storage is filled with flies. When the Mahoganies are on, and we sell 4 dz. Size 14 Brindle Chutes in one morning, we just reach under the bins and pull out 4 dz. more. We care about flies, and do everything we can to make sure we have the flies you need when you need them.

You can’t be a fly shop without Parachute Adams, Pheasant Tail nymphs and Woolly Buggers. Wherever the cycle is on those flies, they’re always in the loop. Believe us when we tell you it would be so easy to just keep a few flies in the shop, the ones that always work, and be done like most shops. But that’s not our job. Our job is to keep our ear to the water, pick up the rumblings of what’s hot on the Bighorn, what’s hot on the Madison. If Trout are eating it on the Snake River or the Henry’s Fork, there’s a good chance it makes a fine meal on Rock Creek, the Bitterroot River, the Clark Fork River and the Bitterroot River.

We all dream of Shupton’s Fancy, Paul Schullery’s fictional fly that “taketh a fish on  every cast.” It’s fictional for a reason! But we never stop our quest of finding or building a better mouse trap. The G Kes didn’t just appear- we tested that fly until we found what worked. That’s what every tyer does before he puts his creation out there, test, test, test. To make sure it does what it’s supposed to, and that’s catch trout. Whether the fly is designed for a specific situation, or is a general use fly, every fly designer secretly dreams of being on the cover of Fly Fisherman as THAT guy who created the fly that sweeps the world. Lefty’s Deciever, the Clouser Minnow, Copper John, Purple Haze- the list goes on and on. And when that fly appears, the Missoulian Angler will have it stock- before it gets on the cover!

We’ll order a lot of Parachute Hoppers for next year. Along with a few we haven’t even seen yet, and the Morrish Hopper, the Pink Lady Hopper and many of the tried and true. A couple might fall to the wayside, and that’s a natural occurrence. We won’t know the hot hopper for next August until next September! But you can be sure the Missoulian Angler will be ready with something old, something new, and full bins of flies, so when you need what’s hot, you’ll find it at Missoula’s oldest fly shop. Experience is one thing you don’t get quickly!

Building Your Euro Nymph Box

There’s no doubt that Euro nymphing, or high sticking to the old timers, is the most productive way to take trout consistently with a fly. Euro nymph techniques provide pinpoint fly control on a tight line, utilizing flies designed for rapid sink rates to quickly enter the zone where most fish live. Whether you call it Czech nymphing, high sticking or Euro nymphing, these techniques have won multiple world fly fishing championships and is effective on the hardest fished waters. Euro nymphing quickly gets your fly where fish are feeding, which is 90% of the battle.

That’s not to say building a box and buying a long rod will instantly answer all your prayers. Like any other fly fishing technique, Euronymphing takes some practice. A slight dip in the rod can result in a quick two-fly loss, while minimizing fly loss lessens your effectiveness. The best Euronymphers walk a fine line between hauling in fish and decorating the bottom. It takes time on the water to find that fine line.

With the bottom in mind, it’s no accident that most Euro nymphers have embraced the jig nymph style fly, for two reasons. First, and possibly most important, the hook rides point up, so it’s less apt to snag in it’s underwater journey. Two, in order to turn the hook over, the bead must be made of tungsten or an equally heavy material. This means jig flies, by their design, sink faster than a fly with a brass bead, thus dropping your fly where it needs to be faster.

Speed in attaining depth is critical with Euro nymphing. Euro nymphing often utilizes a very short cast, giving the fly little time to sink. A well designed Euro nymph gets deep at a much faster rate than a standard nymph. Considering the sink rate of your fly is the most critical aspect of creating an effective Euro nymph fly selection.

Sink rate is governed by two factors- weight and resistance to sinking. This blog writer used to tie the prettiest Hare’s Ear Nymphs, with a nice, active body and super buggy thorax. The only problem was, they wouldn’t sink. Just like a dry fly’s hackle, all those spiky tendrils were trapping air and spreading out in the water, seriously hindering my flies rapid descent in the water. Pretty in the vise ain’t pretty in the water! Too much fuzz on your fly, too much spread, and it won’t sink fast enough.

Which is why the Perdigon style fly, or SR Bullet, is the backbone of any Euro nymphers box. This hard bodied fly is unprepossessing at first, seeming to flout all the widely held beliefs that a fly must be active in the water to look alive and attract fish. Because Euro nymphing is designed to put your fly in a place where the trout doesn’t question its presence, action is less important. If it’s close to looking like food, and skimming across the bottom like the naturals, it’s going to get eaten.

Choosing your first Perdigons is easy. Light, dark, big and small. What could be simpler to get started! The Orvis Co., at one point, had a brilliant idea. They offered a basic mayfly nymph in light, medium and dark. It didn’t sell, as evidenced by its almost instantaneous removal from the catalog. But the concept is smart and useful. You don’t need a lot of accuracy when  putting your fly directly on the trout’s nose. The fish are feeding, taking in as much food as they can, and when your fly is in the trout’s comfort/feeding zone, it’s going to get eaten if it’s anywhere close. Light, dark, big and small.

When fishing in Missoula on the Blackfoot River, Rock Creek, Clark Fork River or Bitterroot River, bigger is often better. In Europe there are very few stoneflies, with many caddis and mayflies. Their fly selections tend to run to the small side, as do many east coast fishermen’s. This makes a lot of sense- match the naturals for more success. In Missoula, we have nymphs that are 50mm long! The small, big, light, dark theory works when fish aren’t focused in their feeding. When trout are on a subsurface “hatch”, having a fly that closely matches the natural is always better. Again, examine the fly for sink rate. The Pat’s Rubber Legs is not our best-selling fly for no reason. It’s the right size, sinks quickly and has good action in the water. A Peacock Double Bead Stonefly is also excellent for imitating the big stoneflies found in Montana. These two flies sink very rapidly and imitate a variety of stoneflies, especially the Pats in its various colors.

Another strong style of Euro nymphs is the Hot Spot. These are jigs with a drab body and a very bright spot of dubbing at the thorax. Some say it represents an egg load in the insect- others just say the contrast attracts the fish attention. We do know flies with a hot spot can be extremely effective, with hot pink and yellow being two favorite colors around Missoula. Again, big, small, light, dark with the added variable of a hot spot.

A third Euro nymph style features a collar of CDC wrapped at the back of the bead, like the Duracell or a Howell’s Shuck-It. CDC is chosen for two reasons. First, it’s easy to work with, can be torn to length and still look natural, and is a light weight fiber with lots of action in the water. CDC also has a property no other feather has. It comes from the preen gland of a duck, and is designed not to mat when it gets wet. The CDC feather holds air bubbles in its fibers that look incredibly lifelike to the fish. But this only works if the feather is dry! Once the CDC is soaked through, it loses it’s ability to trap air, but is still active.

Serious Euro nymphers will carry Frog’s Fanny dessicant with them to refresh the CDC when it’s completely soaked. The Frog’s Fanny pulls the water from the CDC, allowing it to again trap air and bring that natural light refraction to the fly. Dressing your fly after every 4th or 5th cast can be a pain, but there are times when the CDC is a strong trigger, and it’s worth trying if the fishing is slower than you think it should be.

No Euro nymph box is complete without the Annelid. We prefer a basic Red SJW, though Hot Pink is also very effective. A fly that’s often overlooked in Euro nymphing is the Wire Worm. While not a strong producer in Missoula (No idea why not- it SLAYS on the Missouri) it is the fastest sinking fly we sell. What’s not to like- it’s wire wrapped around a hook, and sinks like a brick.

It doesn’t matter what type of bead you use on a size 14 or 16 Perdigon, comparatively it doesn’t sink as fast as a size 4 hook wrapped with wire. The Wire Worm is a great point fly in fast water. It takes your little bug down quickly, and then the long rod controls the depth of both flies. You might pick up a fish or two on the Wire Worm, but your smaller bug sinks deep quickly and doing a lot of business. We all know the addition of lead to your leader adds a hinge point, fouls up casting and is generally annoying to use. The Wire Worm works like a sinker, and has the added bonus of catching fish.

If you’re local to Missoula and are building a Euro nymph box, don’t miss the Missoulian Angler’s Dollar Fly Box on the counter. I know it sounds weird, recommending flies on sale! The Dollar Box is filled with flies that didn’t perform as well as we hoped they would. They were all bought with high hopes- they just weren’t what we hoped they would be. The Dollar Box is incredibly useful as you learn to control your fly’s depth with the long rod and skinny leader. It’s better to lose $2 worth of flies on a cast than $6! So grab a handful of Dollar jigs for when you’re just starting, to save some wear and tear on your wallet.

Because at it’s best, Euro nymphing is about working the bottom of the river, where the fish live. With practice, your fly will follow the contours of the bottom, just as the naturals do. Present your fly naturally, where the food is, and your success rate is going to go through the roof. Too deep, and your flies are gone. Too high in the column, and the fish don’t move as readily to your fly. Depth is critical, and using flies designed to get deep and stay there is a critical aspect of Euro nymphing. Armed with this knowledge, you can build a Euro box that will take trout throughout Missoula, all over Montana and across the country.

Fly Tying – Take Your Season Indoors

Lets start by saying the Missoulian Angler is at the far right on the bell curve. If left is the very casual angler, center is Missoula’s standard out fly fishing 50 days a year, we live on the far right. And if you bell curved the far right, we’d STILL be far right!

All our employees tie flies. Most have been professional tyers, and we all tie flies for the shop.

We started the same way. Someone told us we might be able to save money by tying flies (HA!) or there was a purer joy in catching fish on a fly you tied yourself (true). Now, we tie because we don’t know any other way.

It’s been said that every fly you tie is a little bit of hope for the season. Every wrap of thread is a plan for the next time you hit the water. And let’s not make any bones about it- you think you can build a better mousetrap! As you bend the materials onto the hook, you can’t help but wonder if THIS is the fly that will turn your season around. That’s what fly tying is about . . .

But it doesn’t happen over night, and there’s the rub. Customers come in all the time and say, “I want to tie the Sex Dungeon and the Royal Wulff. Those are my two favorite flies and I’m always out of them.” We always respond with tying flies is great, but you may need to set your sights a bit lower to start. How about a Pheasant Tail Jig and a Pat’s Rubberlegs? Sometimes it’s yes, and sometimes it’s no.

Because fly tying isn’t an art- it’s a hand skill, like hitting a baseball or knitting a sweater. For the same reason you don’t learn to hit facing major league pitching, or start knitting with a multi color, zipper back pant suit, you have to start easy in fly tying. Choose two simple patterns, and start to tie them, like a Pheasant Tail Jig and a Pat’s Rubberlegs! You’ll need tools for tying flies, a place to tie, and the time to spend behind the vise.

And here’s what you get when you start to tie flies. Complaints from your significant other that there’s fuzz all over the house. A bunch of flies that look nothing like the picture on Instagram. Small punctures on the ends of your fingers where the hook inexplicably ended up. A much more varied and colorful way to express yourself when the thread breaks for the 3rd time on one fly. You’ll be in closer contact with your fly fishing buddies, all asking you for “just a couple” of your best bugs. You wonder what possessed you to even start this silly habit.

Until you start to see the other side of the coin. It’s more subtle and far reaching, and it doesn’t come immediately. The moment you tie your first Pheasant Tail, you have to think about proportions. The Abdomen is 60% of the body- the Thorax is 40%. Next thing you know, you find out all mayflies have the same proportions, they just vary in size. Pretty soon, you’re looking under rocks and seeing that the flies you’ve been tying aren’t exactly the right color, so you modify that. Your bugs start to look better to the fish.

All of sudden, the shucks on the side of the river begin to mean more. You’re looking at size and shape, and now comparing it to what you’re making. You begin to make changes to your flies, and they begin to work better.

A grasshopper flies by, and it’s no longer just a hopper. You start to notice the hoppers are different sizes. Some have bright red legs, some don’t. They vary in color, and even a bit in shape. Some have very prominent legs, some are smaller. All this goes into the hopper (get it?!?!) and the next time you’re at the bench, you start to make adjustments to your patterns. They start to look more like a hopper you see on the water, not what others think a hopper should look like. You begin to scope the internet, looking at hopper patterns. You see things you like, you see things you don’t like. You begin to steal like an artist!! You take a body from one hopper and the wings from another. Legs from a third and a head from a fourth. You’re observing things as you’ve never done, and now you’re mixing and matching, learning more every time about what a hopper is and isn’t to a fish. Not all will work, but with every modification, you get closer to a hopper that works for you, that you have confidence in.

That’s the real secret about fly tying. Not that you’ll have flies when you need them, not that they’re better tied and more durable. The real secret of fly tying is now you know so much more. You’re looking at the naturals with a brand new and critical eye. They’re no longer random bugs. You’re no longer reading a fishing report and wondering what it all really means. Without knowing it, you’re learning about insect life cycles, and how and where trout interact with them. You’re seeing how the river works- how water, insects and trout all come together. Wait till you find out about clingers, crawlers and burrowers. All of a sudden, a riffle makes more sense. It’s the breeding ground for insects. No wonder trout stack up in there. You’re a better angler.

All because you took your fly fishing indoors. The moment you set up the vise for the first time, and started bending thread to hook, you’re taking giant steps to be ahead of the curve. Soon, you’ll be looking back and wondering how did I ever catch a trout? I had no real clue what was going on on the river! If you really get the bug (get it?!?!) you’re going to expand your pattern listing. You’re going to take some chances with new and different flies- always with the knowledge you’ve earned, knowing they have a very good chance of working. You’re a smarter angler, you’ve traveled further right on the bell curve.

It’s all about success on the water. At the Missoulian Angler, we learn as much from our customers as they learn from us. A fisheries biologist told us that when minnows hatch, they have no air in their swim bladder. They can’t swim until they surface and take in air. Before that time, they just sort of drift with the current. You have a Eureka moment. You have had nymphs taken as if they were a streamer. This explains it! The trout think it’s a minnow unable to swim. We all tied up some very thin, very small minnow imitations to be used under an indicator. They crush fish when the minnows are hatching. We learned more, and that made us more effective anglers.

Learning never stops on the water. It never stops at the vise either. Not just tying techniques and skill level, but that knowledge that seeps in while concentrating of fly fishing. Everything gets ratcheted up just a bit more, and keeps going. You find yourself stepping into the water with more confidence and greater skill. It’s an upward spiral that never really stops. We tell you that from our combined 100+ years of fly tying experience in the shop.

As the weather changes, and opportunities on the water get fewer and farther between, it might be a good time to think about taking your fly fishing indoors. You’ll thank us next year!

Bitterroot River Fall Fly Fishing

Best Flies For September Fishing In Montana

September fly fishing in Missoula is arguably the best time of year. The water is low, reaching prime temps with longer, cooler nights with the most comfortable wading of the year. The bugs are diverse in size, ranging from size 6 hoppers to size 22 Blue Winged Olives. Subsurface, the nymphing is excellent with so much insect activity, while the streamer fishing comes on as September progresses. It doesn’t matter what type of fly fishing you’re looking for, if you’re in Missoula in September, you’re going to find it. Lets take a look at some of the best flies for September fly fishing in Montana.


September starts with the same flies as you’ve been using since August 10th. The grasshoppers have established, with fish on the prowl looking for a big, easy meal. Missoula hopper fishing starts in late July and depending on weather, may last into November! That’s over 3 months of fish seeing naturals, and their imitations. September is a good time to do a little experimenting with different hopper variations. We carry Pav’s Hopper in 5 different colors, and variations on the Morrish Hopper in 4 different colors. We have gray hoppers, blue hoppers and many pink ones. Why do they work? No idea, but they do. We watch Missoula’s best fly fishing guides shop every morning, and in September they will be looking for full fly bins. The theory is no one is buying them, so the fish haven’t seen too many. Think about expanding your hopper game in September to show the trout

something new and different.


The same can be said for Tricos. In early September, you can almost set your watch by the trico hatch. The fish have been looking at naturals for almost a month, and they can get a bit snotty at this time of year. Think about some Trout Hunter tippet in 5.5X. Trout Hunter tippet is much softer than Rio, and allows your bug to float more naturally. The half sizes of tippet provide more stealth without sacrificing as much strength. Move to trico cripples and emergers, like the Sprout or the Quigley Cluster Midge. Ron’s Trico Spinner will produce consistently as well, though by this time of year he is way tired of tying them! Be ready to drop down to a size 20 as well, so make sure you’ve got your readers when you hit the water.

Blue WInged Olives

We’re all waiting for the magic moment in September- the first real rains of fall. If we’re lucky, the rain comes in about September 10th, and the entire complexion of fly fishing in Missoula changes. The weather change brings cooler temps and some clouds. The tricos trade out for Blue Winged Olives. Same size- different color. The week after the rains will prove to any angler that fish can see color! If you fish a trico through a BWO hatch or vice versa, you’re not going to be anywhere near as successful as you could be. Look for the classic figure 8 of a trico spinner cloud above the water, or get your nose close to the water and check what’s floating by. It makes a big difference!

As the BWO’s start, the basic patterns will work. A simple Parachute BWO or Comparadun will take fish consistently at the start of the hatch. But as the BWO’s extend through September, growing in numbers, the fish get a lot more selective. The Last Chance Cripple or Quigley Split Flag Cripple will start to be more effective for fussy trout. Again, shift down with your tippet size to give your fly the best chance at a drag free drift. Watch rise forms very carefully when BWO’s are on the water. Many fish focus on emerging nymphs, and while you’ll see concentric “rise” rings, it’s the fish’s back that breaks the surface, not the mouth. Drop an unweighted Size 18 Pheasant Tail about 4 inches off the back of your dry and watch your catch rate skyrocket.


In the middle of the month, the Mahoganies start to make their annual appearance. This size 14 mayfly is tough to miss on a Fall afternoon, and provides a steady hatch for the next 3 weeks. The Parachute Pheasant Tail, Purple Haze or Brindle Chute all in size 14-16 are excellent choices at this time, with the Brindle Chute out performing most other flies when the Mahoganies are on, especially on the Bitterroot River where it was invented. Again, as the hatch progresses, start to get a bit more technical with your flies. Bring some Last Chance Cripples or Sparkle Duns when the fish are ignoring your standard fare.

October Caddis

At the end of the month, you can start looking for the October caddis to appear. If you think you can’t miss the Mahoganies, you REALLY can’t miss the October Caddis. This size 8-10 orange caddis is a favorite of fish on the Blackfoot River, Bitterroot River, Rock Creek and the Clark Fork River. If you see one, tie one on. The fish are looking for them and will eat even when the naturals aren’t strong. Both the Orange Elk Hair Caddis and the Orange Goddard Caddis will float a small dropper as well, so make sure to utilize that option as well. The Birds of Prey October Caddis Pupa is deadly subsurface, and if you’re not getting the action you’re looking for on top, get down with the pupa to bring your fish count up.


With all the hatches across Missoula’s rivers, the nymphing can be off the hook! With lower water levels the droppers are shorter and easier to control, especially on the Bitterroot River and Rock Creek. Don’t be afraid to go small. Early in September, the SR Bullet Black in a size 18 is a great trico nymph. When the weather changes the rivers to BWO’s, switch to an SR Bullet Olive and keep raking in the fish. A Pheasant Tail Jig will outperform most anything for the Mahogany nymph, and don’t forget the October Caddis Pupa. It should be said again, if fish aren’t eating on the surface, they’re eating underneath- dry flies get the ink, nymphs get the fish. Especially at the end of the month, when the cold weather tells the fish winter is coming, and they need to eat.


The same weather that moves trout to nymph hard also moves fish to eat streamers. When the days start to get cooler and shorter, a great way to start the day is working a small to midsize streamer around the likely areas. If your streamer choice is comfortable to cast on a 5-6 weight, it’s proabably the correct size. This is conventional wisdom, but there are exceptions. In the big water of the lower Clark Fork River and the lower Blackfoot River (which is now bereft of tubers due to the cold) a big streamer run deep will still work its magic. If you’re a streamer-maniac, the last week of September can be prime time, moving bigger fish looking to take in a few calories before the real weather gets here. Pick your spots to run the Mongrel Meat or Sex Dungeons, or go smaller with a Baby Gonga or Dirty Hippie.

Final Thoughts

Whatever you’re looking for when you head to the water, September fly fishing in Missoula has the answer. Whether you want technical dry fly fishing, prospecting with dries, focused Euronymphing, Hopper/dropper or streamer action, somewhere on Missoula’s diverse rivers you’re going to find it. The weather is relatively mild, the wading is easy, the rivers are at good flows and better temps, and you can expect good days on the water. If you live here, carve out some time to fish during some of the year’s best fly fishing in Missoula. If you’re traveling from out of town, get ready to see some of the best fly fishing Missoula has to offer. We’ll see you in the shop, or hear from you online! 

Insect Biomass

Let’s start out with a few definitions. Insect biomass, for our purposes, is defined as the weight of all insects in a river at any specific time. Carrying capacity is defined as the maximum amount of life that can be sustained in a river system during the harshest conditions. Carrying capacity is always the nadir of population, as the harsh environment removes those less able to adapt to the conditions. That’s enough to be getting on with- more will be forthcoming.

If you look at the graph, there are two pieces of information being tracked. One is the fluctuating aquatic insect population over the course of a year in a river. Overlaid on that is a record of the fluctuating insect biomass over the course of a year in a river. These two pieces of information are critical to understanding the feeding habits of trout in a river.

Let’s follow the line created by the insect biomass in a river. You’ll notice it’s rising in January, and continuing through mid-March, when the insect biomass in the river is at it’s highest. Following the insect population line, you’ll see the insect population in the river is at it’s lowest. Reasoned out, the biomass has peaked because insects have been growing since they hatched, providing more biomass to the river. The insect population is correspondingly low. Few insects are added to the population over the winter, and natural selection and predation has brought the insect population to its lowest point.

And then the first hatches of spring occur. BWO’s, March Browns and Skwalas. As the insects leave the water to reproduce, biomass is depleted. Correspondingly, as the eggs from the spring insects hatch, the insect population begins to rise. However, these new insects are so small, they add little to the biomass of the river, only the population.

As you follow the two informational lines, they diverge until insect populations are at their highest in mid July. Which makes sense, as the bulk of the insects have emerged, and the corresponding eggs have hatched, pushing the population to its zenith. But these newly hatched insects are microscopic, with minimal biomass. By the end of July, the insect biomass in a river is at its lowest point.

These are some of the ramifications of this information. Ever wonder why winter nymphing is so good? With maximum biomass, the trout have access to the most food they will see all year. Jump to July, and the low biomass means food is at its minimum. Combine minimum biomass with the warmer water temps, and you’ve now established the carrying capacity for a river. These are the harshest conditions a river fish faces, and not all fish will survive these critical conditions.

The slash of a fish to a hopper, big fish rising to tiny tricos, the effectiveness of ants and beetles. Behaviors explained by this graph. With such a paucity of food in the river in July and August, fish are willing to be a bit less selective in their eating habits, and range a little farther from feeding lanes to take available food. When a sparkly purple and black thing floats over their heads, there’s a better chance the trout will eat it, because they’re hungrier now than they were in June.

As the natural cycle of insect growth moves on, the biomass of the river begins to recover in late August. Water temperatures drop in September, and the harshest period of the year has passed. The carrying capacity has been established for another year. The insect population will continue to fall, while the biomass rises until we hit March again, and the cycle starts again.

Few anglers use a nymph in a size 18 or 20. Yet this graph clearly shows there are smaller nymphs available throughout the year. As anglers, we get so focused on hatches that we sometimes forget to mimic the most abundant food form, which is small nymphs. The larger trout may not be exactly where you think they should be to take the “prevalent” insect. They may be in a prime location for size 20 nymphs, hoovering up the most abundant food source in the river. Another thought- because many stoneflies are on a two or three year life cycle, stonefly nymphs are always available to the trout. The rubberlegs we all fish so heavily in late spring is still just as effective in the summer and fall, because of the 365 presence of stonefly nymphs.

An understanding of the cycles of food sources in a river can help us understand some fish feeding behavior, and help explain why you can catch huge trout on tiny nymphs. It also may explain the Royal Wulff and Hippie Stomper’s success. Not a truly natural color or shape, but when the fish are hungry, those flies look enough like food to get eaten. Armed with a little knowledge, you may find your catch rate going up in all seasons as you match your tactics to the food source.

Trico Spinner Fly Fishing

The Lowdown on Cripples, Duns, Spinners and Emergers

So much gets written about matching the mayfly hatch. And rightfully so, because when the hatch is at its most intense, the fish are the most focused. They can concentrate on one very particular phase of the hatch, or in one spot on the water column, and if you’re not there, well the trout aren’t going to change their feeding to make you happy!

Trout have an IQ of 4. We use this to set up this example of how a trout feeds during a hatch. Imagine a person with an IQ of 4, standing in front of a conveyor belt, which is bringing things by. Apples, cherries, tomatoes, strawberries, red seedless grapes, raspberries and radishes.  All similar, but different. And all of a sudden, many cherries are coming past and the person at the conveyor belt eats one. It’s good, and they eat again. Imagine the focus needed with a 4 IQ to concentrate on finding cherries. It takes all they’ve got. They lock in, and everything else is out of the picture.

That’s a trout in a feeding lane. They’re on a fly, concentrating for their lives, and nothing is going to break that intensity. As anglers, we might put on a tomato- hey it’s close! But it’s NOT a cherry. It goes by. Same with a raspberry, or cranberry or strawberry. You need to be exact, because the fish isn’t coming out of their little cone of concentration to think of anything else. They don’t have the brain power.

Now, so many cherries are coming down the conveyor belt that some have stems and some don’t. Some are solid red, and some are red/yellow. Again, the person at the conveyor belt gets focused on stems, or no stem, and the feeding process becomes that much more complex. All of a sudden, the person pulling food off the conveyor belt is only eating cherries with no stems that are red/yellow. Yes, there are other cherries going past, but now the focus is tighter, and the food source has become more limited. We think that’s the simplest way to understand what’s occurring during a strong mayfly hatch.

Now let’s get to mayflies. When the blanket hatch is on, like PMD’s, Tricos or Blue Winged Olives, there are many stages of the fly coming past the trout. The fully emerged dun, drying its wings in preparation to fly off. Emergers, which are nymphs breaking their way through the surface film in preparation to become duns. And then there are the cripples. A cripple is a fly that has not successfully made it from emerger to dun. When asked, we say a cripple is simply an emerger that wasn’t capable of becoming a dun. All of these different stages of the same insect are going by at the same time, and like the person at the conveyor belt, the trout will often focus on only one stage.

Quick note. This is most prevalent in a blanket hatch. In contrast, the Green Drakes don’t often come off in huge numbers. They are a sparser emerging insect, and when they come off, there aren’t enough bugs to get the fish focused on one stage. Trout eat the insect that’s going by- dun, emerger or cripple. It takes a lot of bugs to get the fish focused on one stage, and one stage only.

The best guides in Missoula, the best anglers in Missoula and all the shop people will start with a cripple. They often don’t change from that choice, and for very good reason. Nature is a harsh place. If a trout expends 4 calories to move for food, it needs to take in more than 4 calories to survive. We’ve all seen trout come from 5 feet away to eat a hopper. Because the energy expended will be more than replaced with the caloric intake from a hopper. Contrast that with a trico or BWO. Those bugs are tiny, and the reward is much less. A trout will not range far to take in few calories. It’s a fact of nature.

A cripple, to a trout, is a stationary meal. They can’t get away. And that’s critical for a feeding fish. Once the energy is expended, the trout can’t get it back. A cripple is an insect that WILL NOT fly off just at the moment of rising. Again, we’ve all seen fish come out of the water chasing an insect. It’s trying to take in calories to offset the energy expended. It NEEDS the reward at the end of the energy use. Miss that meal too many times, and it starts to die. Not friendly, but true. When an animal is crippled, it becomes easier prey for the predator. Slower to move, easier to eat. Just what every predator is looking for. When there are enough cripples on the water to allow a trout to focus on that phase, they will often do it.

There are more than one type of cripples. You have the failed emerger, caught in its shuck with the wings ¼ to ¾ extended. A cripple may have gotten 10% out of its shuck before failure, or 90%. The wings may be almost fully extended, or maybe just a nub has come out. This is such a boon to the fly fisherman. Once an insect has completely emerged into a dun, they are all exactly alike in size and color (for the most part). But a cripple can vary in length, depending on how far it got in the emerging process. And exact size replication isn’t always as critical with a cripple as it is with a nymph or dun.

The other type of cripple is a mayfly that has emerged, but then ran into problems. Blown over by wind, or simply collapsing onto its side from the energy expended while emerging. Once a mayfly’s wings touch the water, it’s done. They don’t have the strength to pull their wings out of the suction created by the meniscus. Close inspection of the bugs floating by you will sometimes show an insect frantically beating one free wing as the other remains in the surface film. That bug is a cripple, but of the second variety.

An emerger, or a nymph that is breaking through the meniscus, is also exceedingly vulnerable at that time. It takes a moment to get to the surface, push its wings from its thorax through the meniscus, and then crawl out through the hole created to emerge as a dun. It has been likened that a mayfly nymph pushing through the meniscus is akin to a person digging through 3 feet of dirt. Not an easy task. So there are many insects just beneath the surface struggling to get to the surface, and that’s also a stage that a trout will focus on.

Vince Marinaro wrote a book on dry fly fishing called In The Ring Of The Rise. Well worth reading. In that book, he details the different rise forms created by feeding trout. Not every trout that breaks the surface is taking a bug off the surface. That bears repeating. Not every trout that breaks the surface is taking a bug off the surface. In a slow glide, on a still day when the fish are podded up, you can hear the “Chup, Chup, Chup” of fish breaking the surface and taking flies. If you look closely at those rise forms, you will see tiny air bubbles coming from around the take point, A tiny bit of air gets trapped in the trout’s upper jaw, and the bubbles escape when the jaw goes beneath the surface. Chup is the sound it makes.

If only we had a dollar for every time we cast over fish that were breaking the surface but not taking from the surface! We wouldn’t be writing this blog. We’d be retired, and hiring the best guide in Missoula to take us fishing every day!!! When a trout is taking an emerger, it’s eating just below the surface, and its back breaks the water as Mr. Big returns to its feeding station.  And no, the trout is not going to come up that extra half millimeter to make you happy! The best way to handle this is to drop a 6” piece of leader off your dry or cripple, and tie on an unweighted nymph. The short dropper will keep the nymph at the correct depth, and you’ll start to take those “rising” trout. Look for bubbles (or the lack of) to identify those rises.

While we’re on the subject of critically watching rise forms, we’re going to talk about spinners. A spinner is a spent mayfly that has returned to the water to die. The classic form is both wings flat against the water, like a cross, though many spinners will have both wings flat on the same side, and their body curled around their wings. Again, the spinner is a stage of life where it CANNOT escape. The rise form to a spinner is very distinct. It looks as if the trout is coming up and just kissing the surface. Very subtle, very gentle. The PMD’s and Ped’s generate a lot of spinners, and once you’ve started to study rise forms, and see the differences in them, the spinner rise will be quite noticeable. Have some spinners with you, and all of a sudden those fish that went begging are in your net.

Duns. Spinners. Emergers. Cripples. We bandy those terms about like it’s general knowledge, but trust us, that information was hard won. It’s attention to detail that gets you to that point. Learning how trout operate and feed takes time on the water. Watching different rise forms is not easy. It’s tough to take a step back and think when you’re surrounded by trout breaking the surface in a feeding frenzy. But if you take 3 minutes to just look, if you’ve prepared your fly box with the different stages of a mayfly’s life cycle, adding in the failures known as cripples, you’re going to start talking more about how many fish you caught, and less about how many fish were rising!