A Sign of What's to Come
What are Skwalas?
Skwalas (Skwala americana) are a small stonefly (typically sizes 8-12) that hatch on a handful of rivers throughout the Pacific Northwest. Typically, we find these bugs in areas that warm up earliest during the transition from winter to spring — the high desert to the east, and a few pockets of warm valley microclimates to the south.
While small black winter stoneflies are present in modest numbers throughout the winter months on most PNW rivers, Skwalas represent the first “real” stonefly hatch of each new year. Dependent on the geography, we’ll see Skwalas arrive as early as February and peak as late as April. Skwalas are smaller and much darker in color than their larger cousins, salmonflies and golden stones, but feature the same telltale layered wings that sit flat as they crawl and spread out like a clumsy miniature drone when airborne. They’re unmistakable in the air, and up close you’ll see a distinctly olive green hue to the underbelly.
Where to Fish the Skwala Hatch
The Middle Fork Willamette sees Skwalas arrive earliest, typically in mid-February. This hatch primarily occurs above Lookout Point Reservoir, where warm winter microclimates help get these bugs going early. Due to the warmer winters we’ve been having and changes in dam release schedules to aid the upstream migration of critical salmon species, the Middle Fork Willamette tends to experience high water events below Hills Creek Reservoir throughout the winter months. Sustained high flows can adversely affect aquatic insect life. In this stretch, the hatch is modest and varies in quality from year to year. Above Hills Creek Reservoir, the Middle Fork Willamette is a freestone stream, and the presence of late winter Skwalas can be counted on more consistently.
Next up, we typically see Skwalas on the Lower and Middle Deschutes starting in early March. The Middle Deschutes offers a better shot at fish that are actually keyed in on these early-season stoneflies. Interest tends to be more sporadic on the Lower Deschutes, but every once in a while, the river’s redsides get hyper-focused on these bugs and will rise to them as willingly as they would a salmonfly or golden stone in May.
Locally, you might also find Skwalas out and about on the McKenzie River in February and March, but it is not a heavily fished or consistent hatch.
Destination Skwala Trips
If Skwalas are already on your radar, you probably have two rivers in mind — the Yakima River in Washington, and the Owyhee River way out in Eastern Oregon. Neither is a particularly easy drive from the Portland area, although the drive time to high-quality trout water on the Yakima is only 20-25 minutes longer than a trip to the Crooked River. The Yakima is best fished from a drift boat, allowing anglers to cast in toward the bank from midstream. But there are also public access points available to fish on foot, and Lower Deschutes regulars will feel right at home amongst the rocky, high desert scenery.
Unlike the Lower Deschutes, the Yakima is a freestone stream that gets much colder in winter. The arrival of Skwalas on the Yakima typically depends on water temperatures, which fluctuate with outdoor temps and snowmelt. With the travel time required, you’ll want to know this hatch is going strong before you go — so be sure to check in with us at the shop for the latest updates.
The Owyhee River is a multi-day destination for Portland anglers, famous for its feisty rainbows and massive browns. The draw here is big fish in small water. It takes roughly seven hours to complete the 400-mile drive, and typically, putting in that kind of effort at least buys you additional peace and solitude. Not so at the Owyhee, which is just over an hour from Boise, Idaho. There are more than a few avid fly anglers in the Boise area, in case you didn’t know — and there are some folks who jokingly refer to the Owyhee’s Skwala hatch as “The Boise Hatch.” April on the Owyhee is similar to May on the Lower Deschutes, except hundreds of anglers are sharing a river roughly the width of the Crooked. People tend to be courteous and will often share water when asked politely. But if crowds aren’t your thing, the Owyhee during peak Skwala season probably isn’t for you!
Luckily, there’s a workaround. If you’re willing to go early, before the fish have fully keyed in on what seems to be their favorite meal of the year, you’ll have a lot more elbow room. And you’ll still have the opportunity to catch plenty of fish, even on top. Fish key in on this hatch incrementally, and you’ll start to catch them on dry flies a good two weeks before the news gets out and the bulk of the crowds show up. A dry-dropper set-up with a Skwala dry and a teeny, tiny black or red zebra midge — think size 22-24 — can yield incredible numbers during this window. The local weather is far less reliable in March than in April, which helps with the crowds. Aim for colder, overcast days if you want more room to operate.
Skwala Fly Presentation and Patterns
Most anglers who target the Skwala hatch do so with the intention of taking fish on the surface, but trout go equally crazy for Skwala nymphs — particularly in systems that see more modest hatches of adult bugs, like the Middle Fork Willamette and McKenzie Rivers. A brown or olive rubber legs nymph will do the trick, but my personal favorite Skwala nymph is the deadly 20-Incher Stone. I like to combine brown and olive dubbing before laying down wraps to help replicate the mottled appearance of a natural Skwala nymph. The Mega Prince is another excellent subsurface Skwala pattern. In the Willamette Valley, these nymphs remain a dietary staple for trout – even as March Browns arrive and take over as their preferred surface meal.
On top, there’s no shortage of excellent patterns. You can go classic, with a sized-down chubby tied in black and olive – but foam-heavy patterns tend to ride a little bit high, whereas the naturals are small enough to get slightly lost in the surface film. I always have better luck with patterns that are a bit harder to see on the water, like a Bullethead Skwala. For dry-dropper set-ups, I like to strike a balance between the two with a simple foam Skwala that floats well yet still rides low and is made from natural materials.
When stoneflies are on the menu, trout are not leader shy. You’ll want to size your leader in accordance with the size of the fish present in whatever river you might choose — we’ll get into more of that below. But as a general rule, a 7.5 3x leader will do the trick east of the Cascades. In the Willamette Valley, you’ll want to lengthen to 9 feet and size down to 4 or even 5x.
Ideal Fly Rods, Reels, and Lines
Again, this will depend largely on where you decide to fish — but a 9’ five-weight rod, like the Redington Classic Trout, is a good all-purpose tool for this particular hatch. It has enough backbone to cast a bulkier fly and fight larger fish, but won’t overpower smaller trout or cast indelicately on smaller water. A sturdy, fast-action 4-weight will also do the job well, particularly on west side streams. Pair with your favorite matching reel and a weight-forward floating line to help you propel these heavier flies through springtime wind.
Guided Trips
Want to experience this hatch with one of our guides? There’s no better time to be out on the Lower Deschutes than early spring! The weather gets better every day, and you’ll often have what feels like the entire river all to yourself. Book your trip today!
About Joseph Beare
Joseph Beare is a guide for Northwest Fly Fishing Outfitters and a regular contributor to the NWFFO blog and newsletter. A former sports reporter, Joseph has been telling stories about outdoor and athletic endeavors for more than 20 years. As a guide, he specializes in unique trout trips, including local year-round water in winter, alpine expeditions on Mount Hood in summer and spring, and searun cutthroat floats in the fall. You can find him on Instagram @pdxflycollective.