Bitterroot Olive Stonefly

Uses

Imitates adult Skwala stoneflies, a spring hatch that is often missed by Western fly anglers.

How to Fish

Like most other stoneflies, Swalas emerge on land, so adults are not available to trout when they hatch. But some are blown or blunder out of overhanging trees and fall on the water, and females return to the river to lay their eggs.

 
So use standard dry fly presentations near bankside vegetation, over riffles, and just below riffles.