WBFC Fly Fishing EDU
The Skwala Stonefly

The Adult Female SkawlaContrary to popular belief and what has been written in books, magazines as well as portrayed by local Yakima River guides for years, the Skwala Stonefly makes an emergence on the Yakima river in early spring.  Many fly fishermen and guides had thought for years that this was a Golden Stone species.  Just in recent years, have they come around to correctly identify this early spring Stonefly.

When I first began fishing the Yakima in the mid 1980's, the chatter with area fly fishermen and guides alike was always revolved around a Golden Stone hatch that appear on the waters of the Yakima, sometime during the month of  February. 

To me, that always seemed a bit early to see a Golden Stone species.  However, anything is possible since the Central Washington climate and conditions were much warmer than I was use to seeing at that time of year. 

The Kittitas Valley is classified as a semi-arid desert climate and the Eastern Washington desert is only a short drive to the east.  The mighty Columbia River seperates Kittitas & Grants counties and the temperate region between two very different and unique landscapes.

The Montana rivers I grew up fishing hadn't produced a Golden Stone until the early summer months of the season.  After closer examination of the Yakima River Skwala species by a University of Davis entomologist and close family friend, this early spring stonefly was correctly identified as the Skwala Stonefly, not the Golden vareity.

This size 8-10 Stonefly sets the motion for great spring time dry fly fishing.  There are vast numbers of the Skwala Stoneflies in the Yakima and you will begin to see the adult stones typically in mid to late February.  The hatch can begin around that time frame and continue on well into the month of April. 

The reason being that this hatch occurs around our spring runoff period.  When high water events take place, the hatch retards itself and the stoneflies become somewhat dormant again during this period.  Once the river conditions improve, the emergence begins again and this can play out several times a season, when unruly water conditions are a constant.

Their are special patterns for imitating the Skwala and you can find the best one's in our fly shop in Ellensburg.  Most of our patterns were produced by Montana fly tyers replicating the Bitterroot and Big Hole River Skwala Stonefly.

 "For early season fishing this Stone-Fly can provide anglers that have found themselves with the winter fly-fishing blues plenty of dry fly excitement. Water and weather temperatures are usually very mild and the Yakima's bigger trout are hungry and on the prowl. 

We begin to see the Skwala emergence when the water temp reach's 45 degree's, but this smaller olive bodied stone tend to hatch in great abundance when the water reaches 47.  A great time to be on the Yakima!". 

The Skwala Stonefly is common in many streams, creeks and rivers throughout the entire western United States.

The Skwala Stone can be found in California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming.  

There size will range from 8 to16mm depending on the gender of the species.  The female is of course larger as in most stonefly species that are found.

There normal emergence period begins around the middle of February, Water temperature is ususally the key factor in there emergence. 

It must be in the middle to middle to high 40's before we begin to see them emerging in great numbers.  Like many stonefly speices, the afternoon and evenings are the best times to see this stonefly and when they are most active.



Order Family Genus Species Body Color Wing Color Emergence


Plecoptera Perlodidae Skwala Parallela Olive-Yellow Clear Evening


The WBFC EDU is dedicated to educating anglers on all aspects of fly fishing and one of if not the most, important pieces to that puzzle is food.  Under our Insects, Hatches, and Baitfish section anglers will be introduced to the large selection of species that call our river home and our trout call lunch. Anglers will also have an in-depth look at what flies imitate what sources of food and many of those patterns will also have videos under our media section for you to reference when preparing for your next fishing adventure. 

From Stoneflies to Caddis, Crawdads to Sculpin we here at WBFC want you to have access to the most information around when it comes to fly fishing.  The team at Worley Bugger Fly Co. is dedicated to making you into the best fly fisherman possible.  Check the Links below or above to be directed to our fly tying and EDU Videos, our Hatches Index, and our Insect Identification for an in-depth look at food for trout.


1713 SOUTH CANYON ROAD - ELLENSBURG, WA 98926 - 509-962-2033 - www.worleybuggerflyco.com