There are many hatches on the rivers in the Greater Yellowstone that trout feed on. A plethora of stoneflies, mayflies, caddis, midges, and more. We are so very lucky to have a variety of hatches that bring trout to the surface.
That said, I want to highlight the importance of stoneflies in this blog post, since stoneflies are so critical to us anglers and a trout’s diet.
Unique to the West, stoneflies are one of the most sought after hatches in all of trout fishing. They are one of the most important hatches for Western anglers because of the nutrients they provide to the entire ecosystem. Being on the river during an intense stonefly hatch is a sight to see. Not only is the river blowing up from fish eating stoneflies, but the birds are swiping stoneflies out of the air. It is a spectacle of nature that blows me away every time I see it. I can’t stress how truly lucky we are to have stonefly hatches in many trout rivers out West.
Why The Stonefly Hatch Is So Important
There are a few reasons why stoneflies are so important to us fly anglers.
First is the long life they live. Stoneflies have surprisingly long lives compared to other aquatic insects, as some stonefly species can live up to three to four years as a nymph before hatching into an adult. This means they are available to trout year-round and are a common prey item for trout of all sizes.
Second is the nutrients they provide. Stoneflies are one of the largest aquatic insects, so trout get a big meal and lots of calories by eating one insect. Combine their size with their abundant populations, and you get an equation for some fat, healthy trout. I have heard estimates that trout get 70+ percent of their annual nutrients during May and June, when stonefly hatches are most prevalent. That is just insane to think about.
Lastly, stoneflies are important to fly anglers because of their long hatch season. From early spring to late summer, stoneflies hatch across the Yellowstone region. One could commit to chasing the bugs from early April through August, showing how important stonefly hatches are to us anglers all season long.
Stoneflies In The Yellowstone Region
There are many stoneflies found in the Yellowstone Region. The salmonfly and golden stones are the most popular stonefly hatches, usually hatching in May through July. People from around the world travel to the Yellowstone Region for the chance to catch a big trout on a big dry, and the salmonfly and golden stone hatches are the time to do it.
The region also hosts skwalas and nocturnal stones. Skwalas are a spring hatch, and while rather inconsistent, they produce great dry and nymph fishing on the right days. The same goes for the nocturnal stones, though they hatch in the late summer. Nocturnal stones hatch at night and skitter across the surface, providing exciting fishing for those willing to get up early.
Lastly, a variety of smaller stoneflies hatch in the Yellowstone region. The most notable to the fly angler is the Yellow Sallies. Often a size 14 or 16, trout key into yellow sallies in the summer months. They are usually yellow or green and can be found on most rivers in the Yellowstone region.
When and Where To Fish Stoneflies
While stonefly patterns can be effective any day of the year, the best times to fish stoneflies are in the spring and early summer. This is when stonefly activity is highest, and trout are keying in on stonefly nymphs and adults. The months March through August tend to offer the best stonefly fishing, on and below the surface. Even if you are not seeing much stonefly activity, fishing a stonefly dry dropper can be an effective method. The classic chubby-to-rubber-leg is very popular here in the West, and for good reason.
Many fisheries in the Yellowstone Region host stonefly hatches. Tailwaters such as the Madison, Henry’s Fork, and Snake River have great hatches. Freestones like the Gallatin, Big Hole, and Yellowstone rivers are also known for their stonefly hatches. But so many rivers above and beyond the ones mentioned have stonefly hatches, so we have many options to choose from.
There is so much more I can go into when it comes to fishing stoneflies, but I just wanted to stress the importance and uniqueness of the stonefly hatch here in the West. We are incredibly lucky to have a long period during which we can raise trout to size 8 dry-fly patterns. It’s something I find myself taking for granted.
Thanks for reading, and I hope you take advantage of the many stonefly hatches this year and beyond.
I’ll see you out there,
Nick
