We have reports of drastically low water on most irrigation reservoirs to out southeast. Whether or not there will be enough water to sustain fish populations through the winter in these remains a good question. Springfield Reservoir seems to be the exception where midge pupa patterns under an indicators are producing some very nice fish. The same technique seems to produce well around inlets to Mackay Reservoir where water levels are also receding.
Young whitefish dying here remains a mystery so far. Now the same is being reported for the main stem Snake River (below the “South Fork” -Henry’s Fork confluence) and the Teton River. Flow out of Palisades Dam is dropping slowly. Today its down to 10200 cfs meaning little impact on fishing. So keep on pitching hopper and chernobyl-like patterns toward banks and stream-side cover. The storage season is upon us with agricultural needs dropping, so it’s a matter of time for flows to drop significantly. The next big mayfly emergence will be BWOs and mahogany duns in a matter of weeks. Likely by then flows will be at a level better for fishing.
Now that days are shortening and cooling, the best thing for improved fishing is happening. That is waters cooling off to temperatures not dangerous for caught and released fish. A big concern remains on some irrigation reservoirs that experienced deep drawn down deeply because of irrigation demands during our unusually hot, dry summer. We will keep an open ear for conditions going into the fall season and the outlook for next year on these reservoirs and report what we hear on them here.
The next few weeks will be a great time to visit the Blackfoot River above the reservoir. As waters cool the river in the Blackfoot River Wildlife Management Area will offer good fishing with terrestrial patterns. There are about seven miles of river within the area, most of it being classic meadow stream, but there are some riffle and run portions. From Idaho Falls the shortest approach is from Bone east down the Long Valley Road, on around the east side of Gray’s Lake to Highway 34, and on to Wayan. Once there, take a right on the Wayan Loop to the Lane’s Creek Road. Follow this road south to the upper end of the Wildlife Management Area along the Blackfoot River Road. The countryside is gorgeous, so bring a good camera, not only for scenery shots but for the possibility of meeting up with a trophy cutt.
Not much change here since our last report. But as we cool down and days shorten, changes are coming with respect to where to fish on the lake. When we get reports on the best locations for fall fishing, we will place that info here.
With Labor Day weekend passing some welcomed happenings are coming. Crowds fishing the river will decrease substantially, waters will cool thanks to shortening and cooling days, and flow out of Island Park Reservoir will drop in preparation for winter storage. These will result in better fishing conditions all along the river. Likely the lower river will “come back to life” with renewed BWO hatches, continuing terrestrial insect and caddis activities, and increased effectiveness of presenting streamer patterns during low light conditions. The upper river will benefit as decreased flows in Box Canyon will make for safer wading and better approachability there. Above the reservoir big rainbows are moving into the river to feed on kokanee spawn. and throughout terrestrial insect pattens will remain effective until killing frosts. So it is a great time to be fishing just about anywhere on the river.
Flow out of Palisades Dam is at 10300 cfs. With the reservoir about a third full fly-fishers are wondering when flows will be reduced to begin storage. It sure has been a spotty year for riffle fishing, but high water is likely not the only reason. Nevertheless there remains time enough for some enjoyable riffle fishing if and when flow out of the dam drops further. Mean while keep hitting the banks with hopper, chernobyl types, and super renegade patterns, and you will have some success. Don’t forget to include streamer patterns for evening fishing.
Big news here is that the Park has lifted fishing restrictions on the Firehole and Gibbon rivers below their falls and on the Madison River. With days shortening and cooling, water temps have come down to levels better for hosting salmonids. You can now enjoy trout feeding during AM trico hatches and spinner falls as well as presenting terrestrial patterns during day time on these waters previously closed most of the day.
Gulpers are going on in Hebgen Reservoir. Most action is on the Madison Arm, but the South Fork Arm, with more protection from winds, also offers action. We have reports that the river between Hebgen and Quake lakes is beginning to fish well as waters begin to cool. Try caddis life cycle patterns, and switch to streamers when the sun goes down.
Mackay Reservoir at the upper end and Island Park Reservoir around Trude Bay and Grizzly Springs are the best locations for action with bloodworm and midge pupa patterns. Add Springfield Reservoir to the mix where dry damselfly patterns presented around weed channels and springs bring dry fly action. With a big weekend coming up expect company in these places as other still waters with action such as these are few and far between.