Another productive piece of water to target is shallow current margins at the edge of seams and riffles. Winter stones move from highly oxygenated water like riffles to shallow, slow water near the banks to emerge. Trout sit and feed on the transition line separating these two different pieces of moving water because they can expend limited energy and still have access to winter stones drifting with the current. This type of water is good to fish anytime of the year, but it can be much more important for fly fishers in the winter when stoneflies are emerging.
When fishing current margins, try to use a heavy imitation that can descend moderately fast through the water column.
Autumn is one of my favorite times to fish streamers on trout streams, mostly because there’s a presumption trout will feed voraciously on other fish in preparation for winter. There is a lot of truth to that notion. Yet once snow begins to stick to the riverbed, streamer fishing can become an afterthought.
What many fail to realize is numerous forage fish are still available to trout throughout the winter. Moreover, a number of rivers can experience an influx of baitfish in the winter. This is especially the case with streams that have a large number of tributaries. Small tributaries experience a shortage of good fish habitat during the winter months as flows recede and portions freeze. Because of that, many small fish journey downstream to find suitable water to feed and hold. This is the case on my home rivers the Snake and the South Fork of the Snake.
Cutthroat trout spawn in tributaries each spring and early summer by the thousands and their offspring hatch in early autumn, but they will live, feed, and mature on these tributaries until January of their second winter, at which time they migrate downstream to find more hospitable water. At the same time, other small fish that lose habitat to larger, more dominant fish are migrating to more hospitable environs. Thus, winter is a time when there can actually be an increase of small forage fish on many streams.
Other fish that spawn in spring and early summer will do so on river mainstems. That includes members of the Catostomidae family (particularly Utah and bluehead suckers), mottled sculpins, and shiner minnows. By one of these fish’s first winter, it is a full-fledged fry or fingerling ranging from half an inch to two inches long, depending on the species and stream conditions, making them a perfect morsel for hungry trout looking for a lot of calories in one bite.
There is a strongly held belief that it takes a big baitfish imitation to get trout to move in coldwater conditions like the type that exist in winter. The truth is small streamers can be just as effective. More important than streamer size is presentation and a slow retrieve.
Most everyone I fish streamers with in winter employs slow, one- to two-foot-long line strips. This seems easy enough, but I still observe many anglers retrieving way too fast without recognizing it. Try to hesitate your retrieves on a certain number of casts to imitate an injured or disoriented fish. After covering a piece of water thoroughly, go back through it with one or two fast retrieves.
The water you target with streamers should vary throughout the day. Most rivers are at their coldest from dawn until approximately 1 p.m. Prior to that, target deep portions of the water column in riffle pools and at the tail of seams. Deep water can be one or two degrees warmer than water near the top of the water column early in the day. But as things warm in the early afternoon, target shallow water at the edge of current margins and along banks and structure. That water warms faster than deeper water, and at the right time of day, should facilitate your most productive streamer fishing during the winter months.
When you get down to it, a good part of my winter fly box probably looks no different from any other angler’s winter fly box. There are a lot of midge patterns, a good amount of Baetis imitations, and, depending on the stream I am fishing, a decent selection of scuds and Mysis. Everyone should have these flies in their box. They are essential for winter fishing.
But do not overlook other possible trout forage types. Depending on the water you fish and the time of the winter you use them, patterns that imitate roe, little winter stones, and juvenile baitfish can be just as productive as the old standby winter patterns and make the difference between a successful day on the water and a strikeout.
Boots Allen is a fly fishing guide and writer who lives with his wife and two kids in Victor, Idaho. His latest book is Finding Trout in All Conditions.