Riffles possess a high concentration of trout food, which in turn can attract larger trout during certain periods of time. The oxygen-rich environment attracts bug life, which in turn attracts smaller fish, such as sculpins, minnows, chubs, dace, trout, and other species. For me, streamer fishing the riffles is a hit-or-miss proposition. Because larger fish are light sensitive—at least in many of the pressured waters I fish—my success rate increases when I fish during low-light periods. Dawn and dusk, a rain or snow event, or even a cloudy day can get larger trout feeding in the riffles. Larger trout are attracted to the feeding grounds of larger prey, which also feed on insects during lower light periods. I have noticed this time and time again when using a flashlight to illuminate a riffle while night-fishing. The riffles come to life with insects feeding on plant matter, smaller fish feeding on the insects, and larger trout feeding on the small fish.
Riffles are prime feeding grounds for larger trout when the right conditions exist. I find that larger trout positioned in riffles are normally ready to feed and are willing to chase food items. My favorite approach is to cast upstream with a floating line, an 8-foot leader, and a weighted fly. If I want to bottom bounce a streamer, I choose a heavily weighted pattern that will anchor itself, and I can retrieve the fly back at the desired speed. If I want to swim my pattern higher and faster in the water column, I'll cast more across-stream with the floating line and 8-foot leader but switch to a lighter-weight streamer. Casting across a riffle with a floating line creates additional drag, which increases the speed your flies travel downstream. If a downstream belly occurs in your fly line, the fly will move faster as a result of drag. Because of this, you only need to strip line fast enough to manage the slack as the line drifts downstream.
Some anglers prefer to make an upstream mend to eliminate the downstream bow in the line, but I prefer to keep the bow when fishing riffled water. I believe the downstream bow is useful for two reasons: First, it helps maintain control of your drift, as the floating line literally drags your streamers downstream. Drag is often a desired result, especially when fishing streamers, because the floating line acts like a bobber on the surface.
The floating line lying on the faster currents creates tension on the streamer and pulls the pattern downstream. Second, the drag created by the downstream belly (tension loop) helps create more tension during the hook set. Often, the tension created by the tension loop is all the pressure needed to set the hook. You can manipulate the size of the loop to increase or decrease the speed of your streamer retrieve. The larger the loop, the larger the increase in the speed of your retrieve. A smaller loop (created by an upstream mend) creates less surface tension and will slow down the speed of your streamer retrieve. Again, this is assuming we're dealing with a floating line, not a sinking-tip or full-sinking line. Remember, faster currents lie on the surface, and a sinking fly line will sink below those currents, which will result in less tension. A tension loop will also form when fishing a sinking tip or a full-sinker, but the degree of tension is less when compared to a floating line because the sunken section is positioned in the slower currents below the surface.
Another consideration when fishing upstream is controlling your drift.
Fishing streamers in a down-and-across position is easier because of the immediate tension that is created by placing the fly downstream of your position. Upstream streamer fishing, on the other hand, is similar to tightline nymphing—you need to retrieve line fast enough to stay in touch with your drift. For a dead drift, you need to retrieve the line at approximately the same speed as the fly is drifting toward you. If you want to move your fly faster than the current, then you need to retrieve faster than the speed of the drift. This is where shooting through an O-ring is an absolute must. Shooting through an O-ring allows you to maintain control of the fly line. I learned this important lesson in line control while listening to a Lefty Kreh lecture in my early twenties. Lefty said that too often when shooting line during the presentation cast, anglers have a tendency to let go of the line. As a result, there's a delay in line control as you attempt to regain control of the line. In my case, this is because I'm often looking to where my fly landed, so I might completely miss grabbing onto the fly line to begin the retrieve. When fishing upstream in a riffle section, immediate line control is essential, because both the fly and line move downstream at a fast rate. If, for some reason, you let go of the line and cannot grab back onto it after the presentation, it's difficult to regain control.
Remember that riffles run at a faster rate than most other lies. When casting upstream, you must retrieve the line at least as fast as the fly is drifting back to you. If you can't retrieve the fly fast enough and slack accumulates in the line, a trout strike will go unnoticed. For this reason, a floating line offers the advantage of lying on the surface and creating greater tension on the fly, moving it through the riffles. Sinking line and sinking tips can be fished upstream, but I rarely fish them with an unweighted pattern in a riffled section, because of the stratified current speeds in the riffle. Often, faster currents occur near the surface and slower currents occur at the bottom. Think about the stream in cross section: If you were to place two colors of dye (blue in the top currents and red in the bottom currents) in the water, you would notice the blue moving faster downstream than the red. The same happens with your line if you fish upstream with a full-sinking line and an unweighted streamer in water containing fast surface currents and a slow bottom, especially when fishing a longer leader. The sinking line would begin sinking to the stream bottom, pulling the leader down, and it would eventually settle close to the stream bottom. However, it's likely the buoyant streamer would remain in the faster current, never dropping in the slower currents with the sinking line, and eventually move downstream of the sinking fly line. This alignment between buoyant fly and sinking line creates slack when presenting streamers, causing you to lose control of the rig. If you decide to fish a sinking line upstream, you can do a few things to reduce slack. First, use a weighted streamer in combination with a sinking line. It doesn't have to be heavily weighted, but it does need less buoyancy so that it can drop faster in the water column. This is why I would not use hanging flies when fishing upstream—their buoyancy would keep them suspended in the faster currents at the top of the water column. I stay away from deer hair head patterns or any streamer pattern with buoyancy, instead opting for weighted patterns with thinner profiles. To maintain control of the fly when fishing upstream, you need to position the fly line downstream of the fly. This creates contact and control between you and the fly.
There's another option if you're forced to fish upstream with a buoyant fly and sinking line: Shorten the leader length between line and fly. When fishing upstream in water with stratified currents, it's best to fish the pattern and fly line at the same level in the current. Shortening the length between the sinking line and the buoyant fly forces the fly to ride deeper. This is no different from using split-shot with a nymph. If you want your fly to ride higher in the water column, increase the distance between fly and shot; if want the nymph to ride deeper in the water column, decrease the distance. The point is to stay in control of your rig. Trout don't attack a streamer with full aggression all the time; sometimes they gently inhale it. If you do decide to fish a buoyant streamer upstream with either a sinking line or split shot, make sure to keep the anchor (the weighted line or shot) as close as possible to the streamer. While experimenting with upstream tactics, I noticed when fishing upstream in faster water while using a buoyant streamer, a full-sinking fly line, and a 4- to 5-foot leader, the fly would often ride 3 feet downstream of the fly line tip. In other words, that's 3 feet of slack—too much to register a take from a trout.
On the other hand, you can fish the same rig (buoyant streamer and full-sinking line) either across or downstream because the faster surface currents will keep the buoyant streamer under tension as the fly line and fly are downstream of you. Remember, casting your fly downstream places immediate tension on your rig—your fly is going away from you rather than coming toward you. Maintaining line control is easier when fishing either directly across or down-and-across because the rig is placed under constant tension. There are always exceptions, of course, to these guidelines. An upstream presentation is possible with the rig described above when fishing slow-moving water or where current speeds are uniform throughout the water column. You can fish upstream with a sinking line and buoyant streamer, so long as the surface currents are not moving faster than the bottom. What we don't want is for the streamer to be moving downstream faster than the line, which creates slack when casting upstream and retrieving your flies downward. However, if I'm fishing a flat, a pool, or any river section where there are uniform currents, an upstream approach is possible when fishing a sinking line and buoyant streamer. The surface currents will not drag the streamer downstream past the sinking line during a downstream retrieve.
When fishing a shallow riffle with streamers, you may find yourself continually snagging the bottom. In this case, begin casting directly across-stream or directly downstream—
the line will sink slower due to the increased tension. Placing the fly downstream of you creates immediate tension and results in a slower sink rate. On the other hand, if you need to get your flies deeper in the column, you should begin casting directly upstream. Switching from upstream to across-stream will completely change your presentation, but only if you're carrying one line type—
it may be your only chance to adapt to the speed and depth of the water. Trout feeding in a riffle are often more willing to move for a streamer than for a small nymph. When fishing streamers, targeting a specific depth isn't as critical as when nymph fishing, but there are situations in which you need to work the depths. Streamer tactics will trigger a trout's aggressive nature, but we anglers still need to place the fly within a trout's strike zone. We don't necessarily have to bounce bottom, but if we're not moving fish, we need to switch speed or depth. Streamers offer a larger meal for trout, which results in a greater effort from the trout to move toward your fly. For example, fishing a medium-weighted streamer and floating line will produce strikes when fishing riffled water up to approximately 3 feet deep. Even if my streamer rides halfway down the water column, a trout lying on the stream bottom is still likely to move 18 inches upward to grab the streamer. Streamers offer trout more calories than small nymphs, so trout will expend more energy to hunt larger patterns. However, if I'm fishing a 5-foot-deep riffle with a strong current and my floating-line, medium-weighted fly rig presents the fly 1 foot under the surface, a trout resting on the bottom may not be motivated to move 4 feet through the faster currents. As a result, I'd need to change to either a heavier fly, a faster-sinking line, or both.
When fishing upstream in a riffle with a floating line, the fly is often under constant tension, as the floating line is being pulled downstream by the surface currents. Consequently, I prefer to stay away from excessively large patterns; I find trout have difficulty trying to inhale large patterns that are under constant tension. Again, I don't think you need to fish big flies exclusively to catch big fish. Some of my biggest trout have come at daylight when nymphing the transitions between a riffle and a run with a small, rubber-legged Bugger. The transition between a riffle and a run is a prime lie (one that offers a place of protection, a location to eat, and a spot to rest) and the best fish take up these prime lies during low-light periods. This is more true of brown trout; rainbows, on the other hand, can become active during the bright periods of light. If I had to fish one section of a riffle, it would be at the transition between the riffle and the run, where the drop-off occurs. I've found this to be the case during all hours of the day, as sizable trout will hold in prime lies throughout the day. The best fish often hold in such prime lies, and more importantly, they are actively hunting.
When fishing the transition between a riffle and a run, I'll switch from fishing more upstream to directly across-stream. I prefer to fish each individual seam as I would with nymphing, by laying the fly, line, and leader all in the current. This is still a great tactic for fishing a riffle drop-off, but I've experienced greater success when casting and retrieving the streamer parallel to the drop-off. I find that retrieving my flies parallel to the drop-off (often directly across-stream) keeps the flies in the trout's feeding zones. Fishing upstream and retrieving downstream will obviously work, but it takes more casts to cover the water. The key to streamer fishing is covering water fast, but doing so in a controlled manner. Fishing upstream, especially along the edges of banks where the drop-offs occur, covers the areas where trout are likely to hunt—the transitions between the edges and the main current. The same is true when fishing across-stream between a transition of a riffle and a run. I want to move my fly parallel to the drop, as that is the likely holding area of a decent trout.
The same idea holds true if drifting from a boat. In that scenario, you often have one or two casts to cover the water before drifting past the spot. Usually, I want my streamer to move parallel to the drop-off, slightly upstream, as actively feeding trout will likely be positioned in these areas and ready to ambush prey. It's easy to cast straight toward the bank and retrieve the fly back to the bank without actually taking a moment to read the stream bottom before making a cast.
While casting from a moving boat, you only have limited chances to make the cast count. So during your next float, don't just get into the rhythm of casting and stripping. Instead, make fewer casts, but properly read the stream bottom before making a cast; this will allow your fly to drift past more aggressive fish. This may mean making a special cast (such as a curve cast) or manipulating the line to keep the fly moving through prime zones longer.
Remember that some riffles may be too fast to fish upstream. The speed of the current will move your line and fly so quickly downstream that you won't have the ability to strip the line fast enough to maintain control. In those situations, you'll need to find another angle to fish, most likely down and across. My ideal riffle is at least 18 to 20 inches in depth with a medium-speed surface current and a slow bottom where trout can rest in between meals. The medium-speed currents are slow enough to allow me to cast upstream and control my downstream retrieve, while the 18-inch depth provides enough overhead cover to hide a large trout. The depth also provides a cushion of slower water for the trout to rest near the bottom. Bigger trout will grab these prime lies, and I've had excellent success fishing riffles that meet these conditions. The availability of slower water is key. A sizable trout is not likely to hold in a riffle where there's no resting area. If the riffle is too shallow, a slower cushion may not occur because there's not enough depth for the water currents to stratify.
I've had limited success at catching good-size trout during the daylight hours in riffles that are 10 inches or less. Two possible reasons for my lack of success are lack of overhead protection (shallow water) for the trout, along with the trout having to fight the strong current. Nighttime is a different story. At night, big trout hunt the shallow riffles.
George Daniel is a Fly Fisherman contributing editor and the author of the best-selling Dynamic Nymphing (Headwater Books/Stackpole Books, 2011). He is the owner of Livin on the Fly, a fly-fishing educational/guide company. He lives in Lamar, Pennsylvania and conducts seminars and clinics across the country. He is a former team member and former captain of Fly Fishing Team USA, and former head for the US Youth Fly Fishing Team.