“How do you know what fly to use?” That’s a question asked on almost a daily basis. In response, I usually give what I call my “lawyer’s answer” and reply, “that depends.”
There are a lot of factors that go into the decision, and a lot has been written on that subject alone.
Where one is fishing is probably as critical as any factor. Firstly, every river system has its own unique idiosyncrasies. Freestone rivers like the Stillwater and Yellowstone have different aquatic insects than a tailwater like the Missouri or Bighorn. What works on one system may not necessarily work on another.
This also impacts the selection of terrestrial and crustacean fly patterns. Some rivers have them, some don’t. Since insect hatches are temperature driven, the time of year comes into play too. It’s probably going to be futile to attempt to fish a fly that replicates a spring insect in the fall. River conditions in terms of volume and clarity will also impact fly selection because it’s going to impact where fish hold and how the feed.
Although the term “fly” is a general term to cover anything tied on the end of the line, there are basically two broad categories of flies. There are exact patterns, which resemble a natural insect as closely as possible and attractor flies that don’t resemble anything specific, but approximate natural food of the fish.
An exact pattern is where the term, ”match the hatch” comes from. A fly that is an exact pattern will resemble the natural insect as closely as possible. Fish that are feeding selectively often require a specific pattern fly in order to be caught. Profile, size and color are probably the main attributes to consider in any fly selection. Choose a fly that most closely imitates the natural in terms of those factors. Even if not the exact replica, it will likely get the job done.
Attractor patterns are a good place to start when prospecting water likely to hold fish, particularly during the summer season. They seem to appeal to fish based on instinct or reflex. They cover the entire spectrum of fishing conditions, and very often one or another of these flies will produce a fish when nothing else seems to work.
Another factor weighing heavily on fly selection is how the fish are feeding. When fish are actively feeding, or with visible bug activity, it’s usually just a matter of observation to determine what fly to use.
Many anglers observe fish breaking the surface of the water and logically assume they are feeding on the surface and promptly tie on an imitative dry fly pattern. In reality, the fish may have instead been contently feeding beneath the surface. Observing “how” the fish are feeding is perhaps more important than determining exactly what they are feeding on.
Simply figuring out whether it’s on the surface or beneath, and making a fly selection accordingly, will often make the difference between catching fish or not. So pay attention to the rise form.
The other lesson that is often difficult for most of us to learn is when to change flies. If, after a few decent casts and drifts that haven’t produced a hit on your fly, let alone caught a fish, I would recommend making a change.
If fish appear interested in the fly to a degree, but are refusing to take it, consider making a minor adjustment such as the same fly in a smaller size (rarely does one go bigger), or a different fly, but of the same category (i.e., another dry fly pattern).
Another tactic if the fish appear to be refusing the fly is to use a smaller size tippet. If absolutely nothing is happening with your fly, then make a more radical change. If fishing dry, go wet and vice versa. If fishing a nymph, before changing over the rig completely, try adding another split shot if you’re not already bouncing on the bottom.
Finally, try drifting or stripping a wooly bugger and see what happens. The big brown that won’t expose itself merely for a single tiny mayfly, may come tearing after a wooly bugger imitating a distressed baitfish like “Jaws” reincarnated.
Patience is often mentioned as being the most admirable and desirable virtue among anglers, but the ability to recognize and adapt to change may be the most valuable trait. Change can occur broadly from season to season or as frequently as from run to run. While any angler can figure out how to “fish,” the angler who observes and is most willing to adapt to these changes is the angler who has figured out how to “catch.”
With the cooler temperatures the end of last week, the Stillwater dropped significantly and gained some clarity. It’s still holding up, and as I look at the weather forecast, may continue that way for a few more days or week or so. We’re at that point though when it can go any time.
There are still March Browns and Caddis, but dry fly action can be hit or miss. A nymph of some sort fished along the edges may be a good tactic. The clarity on the Yellowstone has improved to the point that there may be a short window to fish the entire river, not just the edges, before runoff hits for good.
Tight lines!
Chris Fleck owns and operates Stillwater Anglers Fly Shop and Outfitters in Columbus.