Anywhere you venture on the upper river terrestrial patterns will bring your best chance for daytime action. This includes fishing along banks and around overhangs in canyon reaches. During evenings look for caddis swarms and spinner falls to produce action.
Fishing on the upper river is best when terrestrial patterns are presented. Evening caddisfly swarms also bring action. With flow out of Henry’s Lake decreasing, larger trout are going to move downstream and out of the Outlet reach of the Henry’s Fork. Look for them to be present in the Tubs and on down through Coffee Pot to Island Park Reservoir. Streamers presented in the evening would be the best way to encounter these fish.
Only the upper river is a Henry’s Fork destination now. Terrestrial patterns will be your best bet, and so will visits early in the day and late in the day. Don’t forget that hair mouse! Because flow out of Henry’s Lake is ramping down, big fish in the Outlet reach will move downstream. Might be worth trying big streamers in The Tubs, especially early and late in the day. When we begin to cool off in September, return to the lower river which will improve for fishing as we move through the fall season.
It’s time to use terrestrial patterns on the upper river. Caddis swarms and AM diminishing spinner falls still happen, but those ant, beetle, horsefly, and hopper patterns seem most effective. Want to fish Box Canyon? During daytime you will share it with innertubers and rafters. So fish there very early in the day or fish from dinner time to twilight. Bead head nymphs and terrestrial patterns presented tight to the bank still work. On overcast days any kind of big stonefly nymph will attract interest.
We wanted to pass on the following information from Kim at the Henry’s Fork Foundation concerning the boat ramp at Ashton.
All – We just received word from IDFG that the boat take-out at Ashton Reservoir will be completely closed on Thursday, July 26. They will be seal-coating the parking lot and road down to the ramp that day.
Please share this information. -Kim
Kim Ragotzkie
Stewardship Director, Henry’s Fork Foundation
& Hold the Line Project Coordinator, High Country RC&D
208-652-3567 office
208-569-9775 cell
Only significant change here is that flow out of Henry’s Lake has been dropped from 100 cfs to 71 cfs. This drop in flow means especially larger fish in the Outlet section will begin moving downstream to find cooler water and more cover. So the best fishing here is ending for the year. Look for further drops in flow as we move through summer. Elsewhere along the river start gearing up for terrestrial patterns being the most effective during daytime hours.
Time to consider terrestrial patterns for best chances of success on the upper river. Flavs are well past their peak, and PMDs are smaller and less numerous. Evenings and late afternoons continue to bring activity because of caddis swarms and mornings bring activity from spinner falls. If you enjoy evening action from caddis swarms but want a bit more solitude, try the lower Coffeepot reach. Flow out of Henry’s Lake remains at 100 cfs, so fishing on the river in the Flat Ranch Preserve will hold up until flows drop when water storage begins on the lake. Look for evening caddis swarms, and PMDs emerging during late morning. But again, expect to have best success through presenting terrestrial patterns.
There are enough flavs and PMDs left to interest fish and make a trip to the upper river worthwhile, but look for terrestrial insects to increase in importance as a food form for fish as we move to mid summer. Want to get away from the crowds at the most popular spots on the upper river? What we know as Henry’s Lake Outlet is really the Henry’s Fork, and as long as a good flow comes out of the lake, good-sized fish will remain there and make it worth the time spent trying for them. The flow out of Henry’s Lake is still over 100 cfs, but is sure to drop as summer progresses meaning the larger fish will eventually move downstream. With the flow at the current level the Flat Ranch part of the Outlet, owned by the Nature Conservancy, is an attractive place to fish. It has a character different from downstream reaches, being a medium-sized meadow stream. It hosts a good mayfly and caddisfly population. Terrestrial insects are important here, and because most of the larger fish originated in the lake, such as damselfly nymph and small leech patterns work very well. Consider trying this part of the river particularly were willows provide overhead cover. Stop at the Conservancy’s Visitor Center just off Highway 20 to check in and observe fishing regulations. Who knows a cutthroat or cut-bow hybrid of the year could be waiting for you.
Brown drakes are winding down on the upper river, but PMDs and afternoon flavs and later caddis make for good fishing during cloudy days like today. Start thinking terrestrials. For now that is ant, beetle, and cricket patterns. Soon it will time to break out hopper patterns, but have you ever tried presenting a hair mouse at dusk….. ?
The upper river offers the best fishing now, with flavs appearing in the PM, AM PMD spinner falls, evening caddis hatches and a growing terrestrial insect population. All this is taking place on the Last Chance-Harriman reach. Box Canyon offers good nymph fishing with you favorite bead head nymphs in medium sizes and with rubber leg patterns. The big event on the river this week on July 12th is the Caldera Symposium which combines science and fly-fishing. This event takes place 8:30 AM to 5:30 PM at Pond’s Lodge. Go to the Henry’s Fork Foundation web site to see details on this event which promises to increase your knowledge on how to approach Henry’s Fork fly fishing and appreciation for its fishery.