Before I go on to list the most effective flies I’ve found for fishing smallmouth bass, I’d like to elaborate on the the significance of fly selection and break these flies down into a few categories. If you’re just looking for a list of flies with images and recipes, go ahead and scroll down.
Flies for smallmouth can vary greatly depending upon the region, fishery, time of year, angler, and conditions. Ask ten different anglers and get ten different answers. It’s highly subjective. I’m a full-time, three-season (spring, summer and fall) guide here in northern Illinois, near Chicago. Streamers, a category of fly which I’ll break down later, are a core part of my fishing program. I’m in a part of the world that’s commonly overlooked when it comes to fly angling, despite the fact that Chicago and surrounding area are geographically at the heart of the native range for smallmouth bass.
My primary fishery is a large river on which conditions change frequently throughout the year. I’ll run drift boat trips on this river from flow levels ranging 600 cfs (cubic feet per second) all the way to 13,000 cfs. Fishable water temps during these months can range from 40 degrees Fahrenheit all the way into the upper 80’s and visibility goes from gin clear to chocolate milk.  
Having touched on these three variables (flow, water temp, visibility), be it known there are several more variables that can dictate what fly gets plucked from the fly box. Barometer, depth, wind, wind direction, sunlight, cloud cover, shade, lunar cycle, angling experience, angling pressure, bird pressure, aquatic insect hatches are more variables that are constantly going through my mind.

With so many variables on the table, it becomes difficult to predict the bite or mood of the fish, and so I’m left wondering each morning as I meet my clients, are we going to have to work for them [the fish], or will it be a numbers day? In all honesty, the former is usually the case and while bringing a wild, native smallmouth to the boat can require some acquired skill, persistence and grit, the pay off is huge and the satisfaction of having earned one of these fish, goes far beyond the “Uncle Bob’s stocked trout pond” experience. And so after seven years of guiding and thousands of hours logged, I’m still left guessing. Therein lies the mystique of fishing and why the river experience never gets old for me.

So with fly selection, I place a good deal of importance on the intangibles. If you’ve had the experience of fishing with a guide or have been in the fly fishing world for some time, you’ve probably heard that a big aspect to fishing any given fly is confidence. I’ll admit that there are times that I will change a client’s fly for no other reason than to instill confidence. I’ll say something half-joking like, “I’ve been saving this fly” or “desperate times call for desperate measures”. A big part of any successful guide’s job is to give these occasional pep talks and keep their angler’s head in the game.

Fish the fly like you mean it. After several dozen or even several hundred fishless casts, don’t become robotic about it. It’s easy to slip into a hypnotic repetition of cast, strip line, repeat. As the boat moves down river, customize each cast to the river’s changing features. Believe that each cast will end with the fish of a lifetime. This is much easier said than done and I’m completely guilty of zoning out while fishing, particularly streamer fishing, which is very active, and even physically demanding. Having faith on the water is a huge factor in success. I can think of countless trips with two clients on board and one was catching disproportionately more fish. Skill is obviously a factor here but I think that believing in each cast is the game-changer.

What I’m arriving at with this is that the fly itself is not the end all, be all. With fly equipment, rigging, technique and the positioning of the boat or angler, fly placement and presentation become other key factors in getting fish to eat. Things like mending line, retrieval speed and stripping cadence can affect where and how the fly swims in the water. For instance, if I’m casting from fast water across a seam toward slow water near the bank, an upstream mend will slow down the fly and allow it to sink, bringing it closer into the likely zone and give a smallmouth a better chance at your fly.

This is where the level of the water column and more expressly, the depth of your fly comes into play. Even with topwater fishing or fishing surface flies, there are specifics about where your fly can be. In my topwater fly boxes, I have flies that float high on top of the river’s surface, flies that ride lower in the surface film and others that wake just below the surface.

It’s important to have every scenario covered from the bottom of the river to the highest point on the river’s surface. So the sink rate of any given fly is the main factor I use to categorize flies for smallmouth bass. Think, sink rate, profile and color, in that order.

On my home water, here in northern Illinois, I’ve found that smallmouth bass rely more on vibration senses than visual senses. I almost never use tippet less than 8lb test. Maybe this is because the rivers here are often stained, with less than a foot or two of visibility, although there are days when fishing 10lb test in clear water works great. I also find that smallmouth here can be predatory and opportunistic. So it’s usually important for streamers and even top water flies to have a profile that pushes water, making them more noticeable.

In my experience, smallmouth can be omnivores, feeding on any food source that becomes vulnerable to an ambush or chase. The big caveat here is the mood of the fish. While there are times when smallmouth are out from their holding lies, actively chasing baitfish, crayfish, and literally fighting over a fly pattern that hits the water, there are periods when smallmouth seem to shut down and become inactive. In other words, smallmouth bass are notorious for collectively shutting down. The up side is that they tend to collectively turn on. This can change repeatedly through the morning, afternoon and evening with out much day to day consistency.
These changing patterns in feeding behavior can leave any angler scratching their head. And it’s why I go to the intangibles, like persistence, grit, confidence and putting in time on the water. There are plenty of days when hard work is what produces, but knowing what fly to choose in any given set of conditions can definitely help out. Here are some of my most productive and proven flies for midwest smallies, broken down in to three categories:

K3 Crayfish Hook: Gamakatsu 60 degree jig Weight: dumbbell eyes UV life flex wrap, buck tail, Krystal flash Claws: Pheasant rump feathers Body: Polar chenille, rabbit, rubber legs

When the river has low visibility, water temps are cool or the fishing is slow, I typically resort to this category. Dredging flies for smallmouth are considered streamers, a larger category of fly that is actively retrieved below the surface and imitates any food source other than small aquatic insects. The idea on these deeper, heavier flies is that they’re going to be retrieved slowly or even dead-drifted close to the river bottom where reluctant or resting fish hang out. I tend to use darker colors (black, olive) for these flies and make sure that they have enough material at the eye of the hook to push water. I’ll usually tie them with weight on the top of the hook shank so that the hook point rides upward. Using jig hooks can also help accomplish this, making them less likely to snag the bottom. Be prepared to lose these flies regularly as they are most effectively fished along the bottom. They average one to three inches in length. I use them to imitate leeches, crayfish and other bottom dwelling fish foods. This is probably my favorite category of fly to fish. Also considered streamers, swimming flies, are fished in the middle to upper levels of the water column. They are typically larger than dredging flies, from three to six plus inches in length. In my case, they almost always imitate baitfish. White, yellow and chartreuse, are common colors for these flies, making them stand out, even through stained water, which can make the takes visual and exciting. Fishing swimming flies and actively and erratically retrieving them can elicit some very aggressive eats from smallmouth (and plenty other species, including trout). They're great for searching bank lines. They can also be swung down and across the current, a traditional method that’s great for covering water, when fish are spread out across mid-river runs and pools.

This category seems to get more attention than the streamers I touched on. Because they are fished on the surface, the take is almost always visual. Topwater or dry flies conjure the classic portrayal of fly fishing. An angler spots a fish, stalks it, makes the perfect cast upstream and watches the fish rise to take the fly. With smallmouth, here in the midwest, it doesn’t usually happen this way. I’d say that dredging and swimming flies bring most of the fish to net, but when rivers around here begin to warm up and visibility increases, so does the topwater bite. Topwater flies that I use for smallmouth are fished as frogs, topminnows, terrestrial insects, dragonflies, damselflies and smaller aquatic insects like mayflies and caddis. Depending what I’m imitating and the mood of the fish, topwater flies can be aggressively ripped across the surface, occasionally twitched or dead drifted.