Skwala stonefly activity (and I'm talking dries here) on the Yakima usually commences when the water temperature reaches a point between 40 and 45 degrees. Sometimes this occurs as early as mid-February. The water temperature at Umtanum yesterday was 38.352 and has been coming up over a degree a day for the past few days. I'll be tying late winter/early spring patterns (again, mostly dry) for the Yakima at the Meydenbauer show this weekend; stop by.