5 Tips to Successfully Fish the Salmonfly Hatch

The prospect of fishing abnormally large dry flies to voracious trout draws anglers from all over the world to the American West every year. The emergence of these big bugs gets everyone’s heart pounding with anticipation. However, it’s not always as easy as throwing three inches of deer hair, dubbing and rubberlegs and catching big fish all day. The Salmonfly Hatch is one of those things you love to hate because it can be so hard to make it productive. There are many factors that can make it a hard hatch to fish successfully. Here are 5 tips to help you avoid some of these pitfalls, and successfully fish the Salmonfly Hatch in SW Montana (and all over the West).

Fish Above and Below the Hatch
As the hatch unfolds it moves upstream everyday. Usually this movement is a few miles a day, but if the conditions are right it can progress upriver by leaps and bounds. Either way try your best to avoid fishing the middle of the hatch. There are simply too many bugs and the fish are spoilt for choice, and also gorge up to the point where they aren’t eating regularly. If possible fish/float just a few mile above the hatch where a few early bugs have the trout looking up, but not over fed yet. Or fish below the hatch. Go fish where the bugs were thick 3-4 days ago. Fish there should still looking up, but the bugs are mostly gone leaving your fly primed to be eaten.

Go Smaller
Salmonflies are large, very large, and the fly patterns tied to imitate them are large also. However, the size of the flies can be a hindrance. Most trout have a hard time eating even the naturals in one bite, and will often swipe at them the first time in an attempt to drown them. So, going from a size #2 or #4 fly down to size #6 (or even a size #8) can allow to trout to eat the fly in one go. This size change won’t affect the number of strikes you get as the most important thing when matching the Salmonfly hatch is color, not size.

Use Larger Tippet
Big dry flies, and especially large stonefly patterns, have a nasty tendency to spin while being cast. This spin with eventually translate up the tippet and leader ruining both. To void this, try using thinker tippet. 2X, or even 1X, tippet sizes are great choices for fishing larger dry flies. Fish aren’t super tippet shy when eating something that big, and the larger diameter tippet takes much longer to spin up. Also, avoid too many false casts!

Single Fly
It is very common to fish two flies at a time here in SW Montana. Whether it’s two nymphs, two dries or dry-dropper rigs we almost always fish two. However, during the Salmonfly Hatch the water levels are usually still high from runoff and the fish are pushed into bank. This means that your fly needs to be running tight to the bank, which can be hard if your dropper gets in the way. So, chop that dropper off and get that big dry as close to the bank as you can.

Don’t Ignore the Other Bugs
Salmonflies aren’t the only thing hatching this time of year. There can be a smorgasbord of insects for the trout to choose from. Depending on the river and conditions these can be other stoneflies like Goldenstones or Yellow Sallies, or other insects like caddis, PMDs, Green Drakes and Brown Drakes. And as much as we want to fish large dries, sometimes (most of the time if I’m honest) the fish feed more readily on these smaller food sources than the big bugs. So, even though salmonflies are hitting you in the head as they fly upstream don’t be scared to try something smaller.