Terrestrial insect season is going on up and down the river. Exceptions include AM trico mating-spinner falls and evening caddis activity. PMD activity is greatly diminished and speckled duns are important only on slow river reaches such as the Flat Ranch and Harriman State Park. When cloudy days arrive streamer fishing will be more effective during mid-day rather than just around first light and twilight. Tiny BWO activity on the lower river is several days away.
Flow out of Palisades Dam was reduced to 8550 cfs (same cfs at Heise, 2770 cfs at Lorenzo) Tuesday. This will make for more walk-in wade fishing locations and increase the mutant golden stonefly emergence.
No change in flow here, currently flow is a bit higher than the average for this time of year, so reduced flows are coming up as irrigation season winds down. Stick to what we suggest in the 8/25/18 report for the South Fork. Mutant golden stones have moved into the lower canyon, but hopper fishing there seems more effective.
For all Fall River Basin streams fishing success boils down to presenting trico life cycle patterns during AM hours and terrestrial insect patterns afterwards. In slower waters speckled dun life cycle patterns can be effective. Mosquitoes are mostly gone, but horse flies have taken over as top rated pest. Expect fishing success in all meadow reaches to slow during mid-day hours. Same applies to all such streams in the Park and outside.
Flow out of Mackay Dam is about normal for the time of year, a bit over 300 cfs, but wade carefully. AM trico activity should be attracting fish, and terrestrial patterns will do the same during daylight hours.
Flow out of Palisades Dam has been reduced to a bit over 9000 cfs ( 9200 cfs at Heise, 4370 cfs at Lorenzo). More safe walk in-wade locations are now available, and look for more to become available as flow will continue to drop as irrigation season winds down. Riffle fishing has slowed a bit. Try #14-16 adams and purple haze in these. With the dropping flow mutant golden stones now coming out on the lower river (see flow at Lorenzo), especially below the big feeder, should be coming out soon from the river above. Terrestrial patterns will be effective anywhere there is vegetated banks along the river.
As with our small streams report, anywhere you try the Henry’s Fork be sure to have grasshopper patterns in that fly box these days. Other events attract trout including evening caddis hatches on most of the river, spinner falls, and speckled dun emergences on the slower portions of the river. But nothing is as totally attractive to trout this time of year as hoppers. Look out for recreational floaters going through Box Canyon, especially during weekends. Anyone seen any honey ants other than around the Harriman section?
The two big dry fly events here are the gulper action on Hebgen Reservoir and the spruce moth fall on the Gallatin and Madison Rivers drainages where pine forests are nearby.
Look at the number of boats on the lake, and slow fishing is obvious. Around springs and creek mouths, especially early in the day, are the best locations for any action. But if action comes to these places, expect company. Looks like best strategy is wait until October.
A fish salvage order is applied to Treasureton Reservoir. Looks like the future of all fish present is limited to a matter of days. Our warm dry weather lasting several weeks results in slow fishing, especially in the smaller, shallower lakes and ponds. Exceptions include Daniels and Chesterfield Reservoirs in early AM hours where fishing at depth (ie midge pupa patterns under an indicator) can be effective. Try bloodworm patterns around Island Park Reservoir springs. Try fishing for warm water species at such as Condie, Johnson, Winder, and Glendale Reservoirs. Or wait until October!