Mackay Reservoir offers the best still water fishing in the area. Fish the river and creek channels coming into the upper end. Midge pupa patterns and damselfly nymph patterns, both under an indicator are good ways to meet action from big rainbows and kokanee. This is a high country reservoir where air is cooling down, so barring big draw-down water should remain cool for good fishing barring a big draw-down.
Best news here is that PacifiCorp, the owner of Ashton Dam has decided not to lower Ashton Reservoir to stop seepage under the coffer dam. See details on the Henry’s Fork Foundation web site on how they plan to stop the seepage. The solution PacifiCorp proposes keeps the best interests of the Henry’s Fork fishery up front, something we all want to happen. Meanwhile go to the upper river around Harriman, Last Chance, and Coffee Pot for best fishing. Go early in the day for the trico activity, switch to terrestrial patterns when they fade out. Switch to caddis in the evening, and don’t forget that hair mouse! If you fish The Tubs area above Mack’s Inn, go very late or very early in the day to avoid the recreational floaters. Try streamers in the deep runs that give The Tubs their names.
So far this season the gulpers on Hebgen Lake have been rather spotty in their activity. No one knows for sure why, but there are a lot of discussions out there on the subject. The peak of activity is usually right about now. Some good advise seems that moving around from location to location as the days go by can bring more success.
Now is a great time to try small streams for action and a good measure of solitude. Off the beaten path, the Salt River tributaries coming out of Idaho are worthy of a visit. Jackknife, Tincup, Stump, Tyhee, and Crow creeks are mainly cutthroat fisheries, but all have more or less brown trout. South Fork of Tincup Creek is all cutts. Early in the day tricos can be seen on each, and by mid day terrestrial patterns bring action, later caddis swarms bring action. Traditional attractor patterns in smaller sizes always work. Lightweight rods (2 to 4 weight) are ideal for each. For sure most of the fish run small, but some large specimens are present and can really fool you.
Early in the day trico hatches (females) and spinner fall (males) is making for good fishing. Wading conditions in the river below the dam are good, too. Switch to terrestrial patterns as the tricos ease off later in the morning.
Trico emergences are making for good early in the day fishing on the Madison River and on Fall River Basin streams. It all ends before noon. After that, switch to terrestrial patterns and hope for a cumulus build-up. The Gallatin River along Highway 191 is fishing very well if you can find a spot in a pull-out. Early AM trico activity is good. Afterwards a switch to terrestrial and traditional attractor patterns works. Later in the day, switch over to dry caddis patterns. The same will work on nearby Grayling Creek, and fewer folks will be fishing there.
Some of the best still water fishing in the area is in the Trude Bay-Grizzly Springs area of Island Park Reservoir. Bloodworm patterns under indicators work when the taking depth is found. Springfield Reservoir is also offering some good fishing. For a change of pace there, try offering dry damselfly patterns. They seem to work well, even when the wind kicks up.
We have not heard of a resolution to repairing the leaking coffer dam above the Ashton Dam. When such a resolution appears, we will post it here. Not much change to fishing action on the river has happened since our last report. An increase in day to day thundershower activity sure would help.
Flow out of Palisades Dam was dropped to 11,000 cfs last night. Let’s see what impact is on fishing, especially in riffles. Several dead or troubled whitefish have been spotted in the river below Byington. Reason for this situation is presently unknown. But IDF&G requests if you encounter whitefish in trouble on the river, but still alive, retrieve them if possible. Pack them on ice (Don’t freeze ’em!) and take to the IDF&G office on Commerce Drive. IDF&G is conducting analyses on collected whitefish in attempts to solve this situation.
Flow out of Mackay Dam is about 350 cfs making for good wading conditions in the river below. Tricos are out in good numbers there. With terrestrial insects abundant and fish taking them and a good late afternoon caddis emergence a trip to fish below the dam is worth considering.