With summer crowds getting heavier and heavier, winter fishing is getting more and more popular in Montana. This is very different fishing than we have in summer, however. The fish are in different places and demand different tactics. Whole books have been written on winter fishing, but the following three winter fly fishing tips will point you in the right direction.
1. Find Warm, Walking-Speed Water from Four to Six Feet Deep
When winter fishing Montana rivers, you have to go where the trout are. The fast, shallow, bouldery areas where most trout feed in summer are devoid of fish in midwinter. The water in these areas is just too fast when trout have slow metabolisms. Instead, the fish gather in large, deep, slow-moving pools where the don’t have to work very hard.
On the other hand, the slowest pools are not the best places to catch fish. Simply put, trout need some current to bring food. So even though there might be a lot of fish in the dead-slow holes in winter, these fish aren’t eating. Instead, look for them along the edges of large, slow-moving current seams. Often the best spots are long midriver seams adjacent to big slow pools, the sorts of places where there’s a gentle interchange of current 100 yards long or more.
By the same token, avoid the very deepest runs. In summer, trout prefer to feed in water 2-4 feet deep. In winter, they may be a bit deeper. That bottomless deep run is unlikely to have any insect activity, because sunlight doesn’t penetrate all the way to the bottom as easily.
Trout are most likely to be feeding in seams that are a little bit warmer than the main river. Perhaps these are areas adjacent to hot springs or hot spring-influenced tributaries, such as immediately downstream of the Gardner River confluence on the Yellowstone or Hot Spring Creek on the lower Madison. Perhaps these are just areas that receive the most sunlight in the winter.
Winter is a good time to bring a stream thermometer. Look for water temps over 38 degrees. Anything colder and the trout tend to shut down. Once the water hits 41-42, you’re really in business.s
2. Fish Low and Slow
What do I mean here? Three things, even though “low” and “slow” are only two words.
First, “fish low.” By this, I mean your flies need to be on the bottom. If you’re not losing an occasional fly in the rocks, you’re probably not deep enough. Most bugs are in the gravel or cobble in midwinter, and even if a few are hatching, the trout are unlikely to move to mid-column to feed because currents are too heavy at mid-depth. The ONLY common exception to ticking the bottom is when heavy midge or BWO hatches occur, which may bring up a few nymph-eaters to mid-column and eventually some dry fly eaters to the surface. We love dry fly fishing here, but we don’t do it in the winter unless we’re seeing rising fish first.
“Slow” has two meanings. First off, your flies should not be “swimming.” If you’re fishing a run that’s moving at a slow walk, your flies should be moving the same speed as the current or just slightly faster if you happen to be fishing a streamer. No skating your bugs, no fast wet fly swings, no stripping & ripping streamers. Trout aren’t going to chase flies in winter.
The second meaning of “slow” refers to how quickly you should move. In high summer, we might cover over a mile of water in an hour on the Yellowstone River on a drift boat trip, and that includes time pulled over changing flies, fixing tangles, releasing fish, snapping pics, etc. Even on foot I might cover half a mile, skipping all but the best water. In the winter, I might fish a single hundred-yard stretch of river for two or three hours.
The fish bunch up in winter, the water they hold in reduces the chances these fish will spook, and the fish are more tight-lipped, requiring perfect drifts to eat. All of this adds up to mean that in winter you’re much better off pounding on one or two good holes than fishing fast and furious.
3. Think Small or Think Big
Here I’m talking about flies. Basically, you have a choice between matching the dominant food items in winter (small stuff), or of giving the fish such a large mouthful that they can’t refuse it. Is it a good idea to fish something big, heavy, and meaty with something tiny on the dropper to touch both bases? You bet.
Most “small” flies should run #16 to #22, with larger flies on rivers and the smallest flies on spring creeks. The predominant small food items you should plan to match are midges and Blue-winged Olive nymphs. If the fish are rising, it’ll be to small midges (or slightly larger midge clusters, imitated with a Griffith’s Gnat) or occasionally to tiny BWO. As winter progresses, a few late Winter Stoneflies might join these insects, though small black mayfly nymphs and black single midge dry flies do a good job of matching these bugs. Also as winter progresses, eggs begin entering the trout’s diet, as early-spawning rainbows start dropping an egg now and again. These eggs should be tiny, either #16 or #18. Even San Juan Worms, which can work on spring creeks and tailwaters, should be sparse and small unless the water (on rivers) gets murky.
Note that pink flies are very good choices on many area waters in winter, especially tailwaters where both early eggs and dead scuds can be matched by pink patterns. Sometimes these run a bit bigger than the typical winter small stuff, but #12 or #14 is still the upper limit.
At the other end of the spectrum are stonefly nymphs and streamers. While you usually don’t want to use the giant #4 nymphs or articulated streamers you might use in summer, a #6 or #8 Girdle Bug or Woolly Bugger is an excellent option. You’re not necessarily trying to match any specific food item except the occasional stonefly nymph. Instead, you’re just giving the trout a great big mouthful: lots of calories to keep warm in winter.
Winter is not the time most visitors think to fish Montana, but if you stick to the tips above and wear waders that don’t leak with plenty of layers underneath, it can be more productive than you might think. Fish in early afternoon when the wind isn’t howling and air temperatures are tolerable.