Big attraction here is the stonefly emergence. Fish are responding best to dry patterns from Lower Mesa Falls to the Chester backwaters. Warm River to Ashton remains a productive float trip for presenting big dry fly patterns. Forget fly-fishing below Chester Dam because Fall River is putting in big time run-off. No stoneflies flying significantly in Box Canyon to date, but big nymph patterns should work any time now. Be sure to have caddisfly life cycle patterns on board when fishing from the Riverside area downstream to Chester backwaters.