Fly Fishing for Trout in Riffles

Reading Water, Finding Trout and Fishing Riffles

Riffle Diagram

There is never a sure thing when it comes to fly fishing for trout. Too many factors can negatively impact the river and the trout and make things tough on the angler. Weather changes, off color water, no hatch, angler pressure or just trout that are not feeding can all create difficult conditions. Even with decent water clarity, strong hatches and relatively happy trout there are times when catching fish is not automatic. But, there are some things anglers can do to come closer to a “sure thing”. The first and most important is to seek out the most productive water in any given stretch of river.

Reading Water

Deep, slow or even dead pools may hold feeding fish at times. Shallow, glassy water might attract trout if there is enough food to make it worth the risk to expose themselves. Roiling, wavy whitewater could be necessary for providing cool, oxygenated flows in very hot, low late summer conditions. Meandering runs with conflicting currents may have rising fish that make it impossible for even experienced fly fishermen to achieve the correct drift. All of these water types may hold fish and they can be caught but there is another water type that is the most productive.

Finding Riffles

By far, as far as finding trout that will be the most willing to eat fly, the best water to seek out first is a riffle. All water is not created equal as far habitat and food production in a river and riffles provide ideal habitat, lots of food and good security for trout. Moderate speed and moderate depth is the key. Choppy but not rough current in the two to four foot depth range will generally hold trout consistently spring through fall.

Winter fish choose deeper, slower water but will push into riffles when the water warms slightly and food sources become more active.  Every year in March though, I look happily forward to the days when more and more fish begin utilizing riffles as bug hatches intensify and temperatures moderate. This is a sure sign that winter is coming to an end.

Food, Cover, Oxygen

Riffles give trout everything they need. Broken surface water creates security cover from airborne predators. Aquatic insect activity is high in riffles. Stoneflies, mayflies and caddis all prefer riffle habitat. Also, in riffles insect nymph, emergers and adults are constantly drifting through a trout’s feeding zone.

Consequently, while trout that found in deep, slow holes, tailouts and elsewhere may be motionless and resting with no interest in feeding, trout in riffles are there for a reason. That reason is too eat. Holding in a riffle does require a little effort and energy expenditure but this is more than offset by the calorie intake that is achieved when a trout feeds in this type of water.

Easy to Fish

Another reason anglers should always seek out riffles is that they are relatively easy to fish when compared to other water types. Slow, glassy pools require a gentle presentation and perfect drift. Not so with riffles. The broken surface allows for a close approach and because the moderate water speed is uniform throughout the length of a riffle it simple to achieve a good drift. A little swing and drag on your fly is not a bad thing in a riffle. As bugs are often actively swimming towards the surface and hatching.

Trout in riffles are often willing to move a chase bugs like emerging caddis with little regard to absolute dead drift. Because these fish are aggressive in nature and many insect species drift by them daily. Riffle trout are rarely as selective as fish in other water types.

Consequently, fly choice is sometimes not as important and general attractor type patterns work very well. Hits on nymph rigs move the indicator noticeably and dry fly strikes are assertive and energetic. Start at the bottom of a riffle and work upstream. During a good hatch, a lot of fish can be landed in a single piece of riffle water.

To conclude

There is no better place to introduce novices to fly fishing for trout in moving water. Guides often seek out choice riffles to teach beginners how to fly fish. There is a good reason why the Madison River between Yellowstone National Park and Ennis, Montana beckons so many anglers and is affectionately dubbed the “Fifty Mile Riffle”. Lots of productive waters sustains lots of happy trout. Luckily, here in Vail Valley, we also have rivers that have abundant stretches of ideal riffle water. The Eagle and Roaring Fork have riffles around every corner.  Also, the Colorado has many long, attractive riffles that hold many more trout than surrounding areas

With winter in the rearview mirror and spring just around the corner, trout in our local Colorado rivers near Vail are now moving into riffles as days lengthen and temperatures rise. Now is the time to book a guided fly fishing trip with Vail Valley Anglers. The fly fishing has been incredible in recent days.

Brody Henderson, Senior Guide and Web Content Writer