Fall is a time of transition, from summer to winter. Many changes occur in watersheds during this time which will affect fall fly fishing strategies for trout. Some changes are obvious, such as cooler ambient and water temperatures, lower stream levels, crystal clear water, and colorful streamside foliage. I took these pictures yesterday along the Piney River in Virginia, which capture the feel of fall that awaits the adventuresome fly fisher.

The Dry Fly Menu

One of the most important changes for both trout and fly fishers is the reduced availability of aquatic insects.  The summer’s major bug hatches are nearly complete. The PMD, stone fly and caddisfly hatches are no longer present. A few trico hatches may be encountered on sunny days, but later in the morning than during the summer months. Some western streams may have mahogany flies, which hatch in the fall. And cloudy days may begin to bring on midafternoon olive hatches. Only the diminutive midge remains reliable, appearing almost daily in the early morning and again in the late evening.

Nighttime frosts take their toll on terrestrial insects, changing the daily menu of these important food sources. Grasshoppers become less abundant, while crickets and beetles seem a bit more resistant to the cold and remain in good numbers. Sunny, warm days may trigger a swarm of flying ants, both black and cinnamon.

Thus fall is noteworthy for its absence of hatches and other surface food sources. With the exception of midges,  the few hatches that do occur are sporadic and hard to predict. In addition, the few available bugs are smaller than their summer cousins.

The Subsurface Menu

Similarly striking changes occur under the water’s surface, where most of the trout’s feeding takes place. Large, mature nymphs are no longer present, having “hatched” into the sexually mature bugs that we imitated with our dry flies during the summer. The eggs deposited by these mature bugs are now developing into small nymphs or larvae. They will slowly grow over the next year, until they become winged flies and complete their life-cycles once again.

Thus fall is a challenging time for trout. Just as they feel the need to fatten up for winter, their robust summer diet of aquatic and terrestrial insects is rapidly diminishing. The few mature bugs that remain, olives and midges, are small, and the developing nymphs and larvae of the other bugs are very small as well. As a result of these changes, the feeding behavior of trout must also change.

With good reason, fall is renowned as the time to fish with streamers. Although streamers can be fished the year around, it is the lack of other food sources in the fall that causes trout to focus their attention on minnows, such as sculpins and trout fingerlings. In contrast to the diminished bug supply, minnows are at their peak. Most fish, with the exception of brown and brook trout, spawn in the spring. Their eggs hatch in a few weeks, and the minnows grow to an entrée size over the summer. This happens just in time to fill the fall gap in the trout’s food chain.

Fly Fishing Strategies

Fall unfolds capriciously, but generally, hints of change usually begin in September.  Once begun, it slowly evolves, until winter snows arrive. During early fall, a few lingering caddisfly hatches may occur, as well as tricos. The caddisflies will be smaller than they were in the summer. As fall progresses, these hatches will stop, leaving only midge and intermittent olive hatches. Consequently, it becomes more difficult to find rising trout, and the flies will be small, size 16-24.

Nymphing will be more productive than dry fly fishing, but will require small flies. I usually fish with size 18-22 nymphs or soft hackles. In contrast, streamer fishing will reach its peak. I usually fish with 3-4 inch streamers, colored to blend with the stream bottom. A streamer with a small nymph trailer is a very productive technique at this time of year. If you want to target really big fish, and don’t mind catching only a few, try fishing with 6 inch streamers.

The month of November usually completes the transition into winter fishing (see Winter Fly Fishing- Strategies for Trout). It is a time for solitude, but if the water is open, the fish will reward your efforts.

In addition to the changes in feeding behavior, brook and brown trout spawn in the fall. Brook trout will mostly remain in the pools or runs of their mountain streams. They will often be found in the shallow tails, looking for spawning gravel. Brown trout that have resided in still waters will migrate into tributary streams to spawn, while those in streams will move from their summer pools and undercut banks to more shallow water, seeking gravel beds suitable for their spawns. Thus shallow sections of stream that we would ignore at other times of the year may very well hold fish in the fall. If fish are present, they will be spooky, and fishing them will require a stealthy approach, and long, small diameter tippets. If you wade-fish for them, watch for their reds, and avoid stepping on them.

Fall is a beautiful time of transition, and the angler who transitions techniques can experience some of the best fly fishing of the year.

Article written by Allan G. Simpson in October, 2014                        Edited December, 2016.