TCO's Skwala Fly AssortmentOne dozen flies chosen by our staff to represent the first major hatch of the season, Perlodidae Skwala, A. K. A the Skwala Stonefly. We have selected 6 dries and 6 nymphs to cover your bases when fishing the Truckee River in the spring. Skwalas in our area begin their yearly emergence in March and on most years, we see them last until June. They are also found on a majority of other rivers here in the most western states such as Colorado, Idaho,