Cool weather has slowed the giant stonefly advance and activity on the upper river. Many recent nights have seen below freezing air temperatures. Giant stoneflies are emerging now as far upstream as Riverside, but are needing warmer weather to become real active. Currently trout are taking caddis, BWOs, and march browns here and on the lower river where big stoneflies are more active. With warm weather and resulting active stonefly activity, look for trout to take interest on the upper river. Who knows if the big bugs will fly in Box Canyon by the upcoming weekend. All depends on the weather!