As the snow melts and our western rivers warm, anglers all over the west trickle onto the rivers. Why you ask? A combination of cabin fever from a long, cold winter and the first big bug hatch of the year. The Skwala Stonefly.
The skwala hatch has provided some of my best fishing over the last few years in Idaho and Montana. Depending on the watershed, this hatch occurs in the Greater Yellowstone Region from February through May. Though it can result in great fishing, it is a difficult hatch to find and effectively fish due to volatile spring conditions. Many anglers do not know about this amazing spring hatch or fail to give it the credit it deserves
I suggest you keep it in mind each spring and do the work to see for yourself the tremendous fishing this hatch can offer early in the season. Here are a few tips I have found important to my success fly fishing the skwala stonefly hatch.
Monitor Water Temperatures
Water temperature is the most important factor when it comes to any bug hatch, but especially the skwala hatch. With inconsistent spring weather, many rivers’ temperatures and flows fluctuate differently from year to year. While this hatch usually occurs before spring runoff, a warmer spring can cause rivers to run high before seeing fish key on the adult skwala. Alternatively, a cold spring will push this hatch a few weeks later than usual.
The water temperature you are looking for is between 40 and 47 degrees Fahrenheit, with the adults hatching in the 43-degree range. Monitoring water temperatures on your rivers is key to timing this hatch. On the days I experienced poor skwala fishing or mistimed the hatch, I was too excited to fish the hatch, and the water temperatures were not warm enough. To clarify, these temperatures should be the highs for the day, and the longer it stays in this range the better.
Understand The Hatch On Specific Rivers
Many rivers in the west experience a skwala stonefly hatch, though it is more abundant and popular on some. Understanding when the hatch occurs on your stream and the unique qualities specific to that watershed is important for success during this hatch.
In general, the lower elevation streams experience this hatch first. This relates to water temperature, as these streams warm first. Some of my best days fishing this hatch occurred in late February on these lower elevation streams. You will then begin to see it on many streams in mid-March through late April, as this is prime time for the skwala hatch on rivers in the area. I would also like to point out that a few rivers stay colder than others throughout the spring, so a hatch of skwalas in mid to late May is not uncommon.
Just because a river is not known for an amazing skwala hatch, does not mean you can’t have great skwala fishing. Out of respect, I will not name any rivers here, but I have found some great fish prospecting with a skwala dry fly on rivers that see a minor or less known hatch of skwala stoneflies. It’s a great time of year to get out and explore before the crowds flood the region, and you may just find some fish willing to eat a big dry fly where you least expect it.
Look For Signs of The Hatch
After scouting out your local rivers and checking water temperatures, it’s time to explore the river. The first thing I do when I get to the water is check the banks for signs of the hatch. Flip some rocks in the shallow riffles and on the rocky banks looking for skwala nymphs and adults. As the day goes on and water temperatures warm, the greater chance you will see more adults on the banks. Skwala adults will hatch during the warmest part of the day, so do a few checks throughout the day and into the evening to confirm bugs are prevalent in the system.
Fish Both Life Cycles
As water temperatures begin to hit 40 degrees, the chances of seeing all forms of skwala stoneflies greatly increase. Many anglers want to throw the big dry fly and for good reason. I will say though that some great fishing can be had on the nymph stage in the weeks preceding and during the hatch.
The skwala nymphs will move into the shallows and hatch when conditions are right. With increased activity in bugs, fishing your favorite stonefly nymph can put more fish to the net than a single dry fly pattern. I have had great success fishing a rubber legs under my dry fly during stonefly hatches. This has some surprisingly nice fish that eat the nymph in shallow water close to the bank. Don’t be afraid to fish a double nymph setup with a heavier stonefly nymph in deeper runs as it will be effective as well.
Trust the Big Bug
Now that I said fishing the nymph stage can be more effective, we are not chasing this hatch to nymph under an indicator all day. We want to catch them on the big dry fly. One of the most important tips I can give to anglers looking to fish this hatch is to be confident throwing the big dry fly all day.
You may not see many (if any at all) adults, but that doesn’t mean the fish in the river are not looking up. Some of my best dry fly skwala days have been on days when I only saw one adult stonefly. It blows me away sometimes, but don’t discount the fact that these trout are coming off a long winter and are opportunistic for a big bite.
I’ll also note it is a great time of year to find some quality fish on the dry fly. Even if you only get a few eats throughout the day, they are usually quality fish. The big browns especially like coming up for a well-presented skwala dry fly as they are looking to put on weight early in the year.
Fish the Proper Water Type
Fishing the correct water type is the last tip I have for fishing the skwala hatch and one of the most important. As much as we wish it was, this is not salmon fly season where they hold in fast buckets and smash your dry fly as it goes over them. The fish in the spring are dealing with cold water temperatures and not looking to expend that much energy. While they start to spread out as the skwalas move toward the banks, trout still hold in slow water that protects them from danger. Whether that protection is depth or structure, these are the places you want to fish the dry fly.
Slow, deep buckets close to the bank that provides structure are prime holding water for fish looking to eat a skwala. A reminder I have for fishing structure is getting your dry fly as close as possible to the structure. I often hear “I was right on that log how did that not get eaten?” when in fact they were 6 to 10 inches off the log. If you can be accurate enough and thread the needle to land the fly between 1 and 3 inches off the structure you’re fishing, it gives you a greater chance a fish comes out from under and eats your fly.
Fly fishing the skwala hatch is a must for all anglers in the West. It can provide stellar dry fly fishing without the crowds many other hatches bring. It’s a time of year I look forward to and a great way to knock off the winter rust and hone in your dry fly skills for the upcoming season.
I hope these tips shed some light on fishing this popular spring hatch, and you can apply them on your next spring outing. Let me know what you would add to this list and send me your stories fishing the skwala hatch. I’d love to hear from you!
