Terrestrial insect patterns bring the best action on all park streams this time of year. This is a fact, but trying a dry adult damselfly pattern brings the same response on still waters and slow moving reaches of all streams. Give one a try. You will be pleasantly surprised. Beula Lake continues to offer the fastest action in the park, and presenting a dry damselfly pattern there will cut you off a chunk of it.
Tricos are coming out from the river below Mackay Dam. Fish there key on terrestrial insects later in the day.Only “fly in the ointment” is that flow out of the dam is around 400 cfs making wading a bit tough.
Flav emergence is ongoing from Palisades Reservoir tribs ( Bear, Big Elk and McCoy Creeks) and Palisades Creek. That event is at its best on Big Elk Creek. Kokanee are going up Big Elk Creek. They do not bother cutthroat from taking dry flies, but their presence brings on some illegal action in the form of snagging. Idaho Fish and Game asks that you inform them of any such activities. The river below Warm River Spring is fishing very well for those folks presenting terrestrial patterns and caddis life cycle patterns. Speaking of terrestrial patterns, this is the time of year when they are effective on all of our streams, big or small.
Flow out of Palisades Dam has been around 9500 cfs for several days now. That is about 1000 cfs than the mean flow for this time of year. Water temperature is up to 63 degrees F. and gets a bit higher on going downstream. Expect flow out of the dam to decrease as the reservoir is only half full. Water storage will begin in preparation for next year’s irrigation season. Riffle fishing is off its peak, but presenting terrestrial patterns toward well vegetated banks results in some good fishing. So does waiting until evening when caddisflies become active. Trail an ant pattern behind your hopper pattern, and action will result. Remember that with cooling weather and less daylight the mahogany dun and BWO emergences are not far away.
Water is warm everywhere, but with decreasing hours of sun light cooler waters are coming and will help bring action. Chesterfield Reservoir water is low and warm with extensive weed growth. The same goes for Treasureton Res. where a few big trout and bass have been caught, Springfield and Twenty-Four Mile Reservoirs are also low and mossy enough to interfere with fishing deep. On both places adult damselfly patterns can be effective when presented over channels between weed beds.
The cooler mornings and evenings are just the ticket for keeping these waters cool enough for fish not only to remain active, but to have a better chance of survival when subject to catch and release. This really is the case for shallow water bodies such as Sand Creek Ponds #2 and #4. Pond 4 is fishing well for those folks presenting speckled dun life cycle patterns, with evenings being a great time to be on the water. The Trude Springs area of Island Park Reservoir continues to produce for those offering midge pupa patterns at depth. To the southeast, Daniels Reservoir seems to be the best bet. Although speckled dun emergences there are sparse compared to such as Sand Creek Ponds, their life cycle patterns are working well. Want to try a different still water? Snow Creek Pond, also known as Teardrop Lake, has holdover rainbows. It’s ideal for flotation devices. Get there by taking the Snow Creek Road off the Fish Creek Road which leaves at Warm River Campground. Dry damselfly patterns seem to be producing well on both Chesterfield and Springfield Reservoir. Water in Chesterfield Reservoir has dropped considerably, but enough remains for ‘bows at moderate sizes to provide good fishing.
Flow out of Palisades Dam has been raised about 800 cfs in the last day. Water temp there is 62 deg. F. Water temp at Lorenzo is 60 in the same degrees. Water there is less influenced by what comes out of Palisades Dam, so loses heat by radiation more quickly. Mutant golden stone emergence is the big attraction now. Look for them emerging early AMs from slower water, near drop-offs, and heading toward vegetated banks. Fish know they are moving, so use your favorite nymph patterns for action. Riffle fishing has slowed a bit, but is still productive with mainly pink alberts emerging. Slamming banks with hopper and chernobyl types is also productive. Try two fly rigs like a chernobyl type trailed by a hopper or ant. Responses by fish to late afternoon caddisfly activity continues to be good.
Flow out of Mackay Dam had been pretty constant at around 340 cfs ( very near its mean flow for this time of year) for the last several days. This AM, however, it was upped to about 430 cfs. That’s a pretty good jump for this small river, so wade carefully. Any day now tricos will be the major emergence, so be ready to try the river during the AM hours.
Flavs are emerging from all major Palisades Reservoir-South Fork tribs. This event is an afternoon happening because waters must warm to around the mid fifties in degrees F. for the bulk of the insects to emerge. Big Elk Creek will soon be crowded because kokanee (redfish!) are already in its lower portions. It’s a fun time of year on all small streams because hoppers and other terrestrial insects are numerous on banks, and trout know they are present. So pay particular attention to presenting around and underneath overhanging vegetation and when breezes move such around!
If you enjoy fishing small streams being in this area right now is like being a kid in a candy shop. July and August have seen a surplus of rainfall in much of the area which helps these streams maintain good flows with water temperatures more suited for active fish. The “where to go” choice is almost endless, and we can help point out some of these depending on your preferences. So for now let’s just point out the few “where not to go” locations.
Water flow out of Blackfoot River Reservoir is variable enough to slow fishing in the river below.
Robinson Creek is down to base level and therefore warmer making fish migrate downstream to deep holes such as near Teton View Estates on downstream.
Pine Creek is slow fishing for much the same reason as for Robinson Creek.
Shallower beaver ponds on such as Jackknife and Tincup Creeks have warmed enough that during afternoon hours fish there will move to riffles above in order to find more dissolved oxygen.