Pro Tips: How to Fish the Skwala Hatch

Written by: Kyle Wilkinson, Ellensburg Angler

Angler Derek Dewey with a fine Yakima River rainbow that fell for a Skwala imitation.
All photos courtesy Kyle Wilkinson

The Skwala stonefly hatch may be one of the most anticipated of the year in the West and Northwest. Perhaps it’s because we’ve only recently brushed the snow off our coats and chipped ice out of our drift boats. Or maybe it’s because the Skwala hatch provides one of the best chances all year at the largest trout in the river. 

We often start to see our first Skwala adults on my home water—Washington’s Yakima River—`in the first week of March. As river temperatures begin to creep into the mid-to-upper 40s, we start seeing more and more Skwalas popping off and more fish keying in on the adults as they land on the surface.

Dry-Fly Fishing

At the start of the hatch, you can get away with larger dry fly patterns like a Chubby Chernobyl (sizes 6-12) in olive or peacock. As the hatch progresses and the fish start experiencing more pressure from anglers, smaller flies or patterns with a low-profile like a Bullethead Skwala (sizes 8-14) can be a lot more productive when fish become picky.

An early-season Skwala rests on a riverside snowbank before taking flight.

A great setup for fishing dry flies during the Skwala hatch is a 9-foot 5- or 6-weight rod. You have a good chance of hooking a truly large trout, and you may need some extra backbone to fight such a fish in current. The fish usually aren’t particularly spooky, so you can use a 7-1/2-foot or 9-foot leader tapered down to a 4X tippet. 

During the peak of the hatch, try fishing a double-dry setup, with a large-profile Skwala up top and a lower-riding pattern on an 18-inch dropper. This will help you see your flies on the water and provide an opportunity to pick up those finicky fish. This setup can also be productive as March browns and blue-winged olives start hatching. 

Target rising fish near woody structure, submerged boulders, or drop-offs. Boulder gardens and shallower banks can be good places to look for risers. If dead-drifting patterns aren’t drawing strikes, try twitching your dries to add a bit of movement. Slight twitches, just enough to move the legs or ripple the surface, is plenty. 

You can also fish a dry-dropper rig, with a nymph on 2 to 3 feet of 5X fluorocarbon below a high-floating dry. A thinner diameter fluorocarbon tippet will allow your flies to cut through the water easier. Good nymph patterns for this include a heavily-weighted Pat’s Stone (sizes 6-10) or a Tungsten 20-Incher Stone (sizes 6-10). Note that if you fish a nymph off the back of the dry, it needs to be able to sink fairly quickly through the water column and stay at depth throughout your drift.

Skwalas are the first big hatch of the season, bringing big rainbows to the surface.

Nymph Fishing

For most of our nymph fishing, we run a 90-degree nymphing rig, which allows our flies to sink quickly to the bottom and stay there throughout the drift. Tie a perfection loop on each end of a 12- to 24-inch section of heavy monofilament (14- to 20-pound test) and loop one end to your fly line. This is the section of the leader where you’ll attach your indicator. This heavy section of leader allows for the adjustment of depth depending on how long you tie it. The thicker line is also easier for mending and turning over heavy nymph rigs in the wind. Next attach 2 to 3 feet of 3X fluorocarbon line to the open loop. On this section of leader, slide a short piece of surgical tubing to anchor a tungsten BB against the leader. This allows you to adjust the depth by moving the bead up and down the line to best fish the water. Next, tie on a section of 4X fluorocarbon with a double or triple surgeon’s knot to keep the tungsten BB from sliding down the line. Tie on some sort of stonefly pattern. Our favorite is a coffee Pat’s Stone (sizes 6-10). Off the bend of the hook of the stonefly, add 18 inches of 5X fluorocarbon tippet and tie on a worm pattern, small midge, or another stonefly. 

Look for fish to be holding at the mouths of tributaries and along drop-offs or submerged boulders. Current seams where fast and slow water meet can also be good holding spots. As the hatch progresses, fish will begin moving closer to the bank and along shallower gravel bars as fish begin picking up nymphs preparing to hatch. 

From upper left: Pat’s Stone, Chubby Chernobyl, Tungsten 20-Incher, and Skwalameister.

Don’t Wait to Get Out

While the Skwala hatch is one of the most anticipated hatches of the year, it doesn’t last long. Once the hatch gets going, you have only about a month’s time to capitalize on it. Skwala hatch duration—as well as start and end dates—vary depending on the watershed you are in. So blow the dust off of your dry fly box, and we’ll see you on the river. 

Kyle Wilkinson is a guide and the social media director for Ellensburg Angler, an Orvis-Endorsed outfitter on the Yakima River in Washington State.

2 thoughts on “Pro Tips: How to Fish the Skwala Hatch”

  1. Appreciate the article. I will try to fish the Skwala hatch in Montana this April. I don’t understand how the surgical tubing works. How long is the tube, what is the diameter, and is the shot above or below it? I have an old friend in Yakima and look forward to getting him off the mountain sides and into a drift boat! Appreciatively,

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