Understanding the Skwala Stonefly Hatch in Oregon
The Skwala stonefly represents one of the earliest significant hatches of the year in Oregon, offering exciting early-season fishing opportunities for anglers. This guide covers everything you need to know about this important aquatic insect in what we hope is an easy to digest format.

The Skwala hatch occurs every spring both east and west of the cascades as well as north in the state of Washington. Rivers like the Owyhee and the Yakima are regarded as the best fisheries for the Skwala, however rivers like the North Umpqua, McKenzie, Middle Deschutes, Lower Deschutes, and Crooked Rivers all have Skwala hatches as well.
Aside from the March Brown which we have covered in a previous blog, this is a large meal for trout who have been starving for a big cheese burger, so it is important to understand this hatch and be prepared on when, where, and how! That is what we aim to do in this list style format!
The Scientific Section
- • Order: Plecoptera (Stoneflies)
- • Family: Perlodidae
- • Genus: Skwala
- • Notable characteristic: Often referred to as "short-winged Spring Flies"
- • Size: Adults typically measure 15-20mm in length
Skwala Life Cycle
- Duration: 2-4 year aquatic phase
- Stages:
- Egg stage (deposited in water)
- Nymphal stage (2-4 years underwater)
- Adult emergence (early spring)
- Breeding and egg-laying phase • Habitat preference: Clean, well-oxygenated rivers with cobbled bottoms
Timing the Hatch in Oregon & Washington
East of the Cascades:
- Primary Emergence Late February through March
- Peak activity: Mid-March to early April
- Best fishing times: Late morning to late afternoon
West of the Cascades:
- Primary emergence: Early March through April
- Peak activity: Late March to mid-April
- Weather dependent: Activity increases on warmer, sunny days
What Type of Water to Fish

- Riffles: Primary feeding zones
- Seams: Between fast and slow water
- Bank edges: Important during egg-laying activity
- Boulder pockets: Preferred holding water for feeding trout
Tactics and Techniques
Surface Fishing:
- Time of day: Late morning through afternoon
- Weather: Sunny, calm days are optimal
- Technique: Focus on foam lines and seams
Subsurface Fishing:
- Nymph fishing: Most consistent method
- Target areas: Deep runs and riffles
- Depth: Fish close to bottom in feeding lanes
Pro Tips for Success
- Watch for adults skittering on the surface
- Focus on cloudy days for better dry fly action
- Use two-fly rigs with a nymph dropper
- Pay attention to water temperature (optimal: 42-52°F)
Conservation and Environmental Considerations
- Indicator species for water quality
- Sensitive to environmental changes
- Important food source for native fish
- Requires clean, well-oxygenated water
The Skwala stonefly hatch represents one of Oregon and Washington's most anticipated and significant early-season fishing opportunities. Understanding their life cycle and habitat preferences will help you make the most of this exciting time on the water.