Some cloudy weather sure would help increase the BWO emergence. It looks like the beginning of next week may bring some. The river has stabilized with respect to flow changes. The last drop was back on September 14th, and responses from fish are back to normal. However, the reservoir is less than twenty per cent of capacity, and storage for next year’s irrigation season must begin. So more decreases in flow out of Palisades Dam must be expected in the coming weeks. As we learn of these flow changes, we will post them here and advise how such should impact your South Fork fishing strategy.
Mayfly emergence events on the upper river are diminishing quickly with colder weather setting in. Soon that of BWOs will be the only one available. Almost on key flying ants are coming on to provide action from trout which seem to crave them. So add ant patterns to your terrestrial pattern roster when you venture to the Last Chance , the Harriman State Park reach, and the river around Hatchery Ford.
Some storms were in the area this last weekend, and we got some reports of good responses to Firehole BWOs during overcast conditions. Other than that, terrestrial patterns most likely are your best bet during daytime. With a bright atmosphere one must be stealthy, so long floats especially to the opposite bank, fly first would be the best strategy on such crystal clear waters as Slough Creek, Soda Butte Creek, Bechler River, Fall River, and Boundary Creek. Other choices for good fishing would be the morning trico mating-spinner fall activity on many of the Park waters or early or late in the day streamer fishing in waters where brown trout are stocking up and beginning spawning migrations.
Only a few reports on good fishing here to date, but they are sure to come as lowering flows make the river more accessible. For now, where wading is safe, try presenting streamer patterns when first light reaches the river or beginning about sunset. Caddis are also active during evenings, and if we ever have overcast or storms again, look for BWOs to emerge and fish to respond.
Air temperatures drop into the teens during night time now. That’s the reason for fishing picking up on the Firehole River. That drop in temperature also helps convince browns and ‘bows to leave Hebgen lake to spawn. So the gulpers are gone for the year there, and the bigger ones now are more interested in heading up the Madison, the South Fork of the Madison, Cougar, Duck, and Grayling creeks. That means you need streamer pattens for the best chance to meet them.
Sand Creek Ponds are offering some good fishing with waters beginning to cool off. Wind is a frequent visitor to these ponds, so consider presenting grasshopper patterns around shorelines there. The Grizzly springs area of Island Park Reservoir is still producing good fishing for those presenting blood worm patterns, and some big ‘bows can still be found where the river enters the reservoir. Streamers would be the best bet for success there.
We have heard of no big change from the creek mouths and spring holes being the places to fish on the lake. These locations still attract a lot of interest because so many other regional still waters have been drawn down to the point where they offer marginal fishing. Thus many “displaced still water anglers” are heading to Henry’s Lake to enjoy some good fishing. That means expect company at these favored locations
If you look at our experience fishing the lower Blackfoot River in our Small Streams report today there are words on the effects of aquatic weeds breaking up. Those words apply, as well, to sections of the Henry’s Fork that “weed up” during the growing season. That includes such as the Harriman State Park reach, the River above Mack’s Inn, above Coffee Pot Rapids, and others. What is important regardless of the water you fish, weeds breaking up this time of year release life forms that therefore become more easily available to foraging fish. Thus because of availability they will key on these life forms and your response should be to simulate them in the flies you offer.
We fished the Blackfoot River several miles below the dam a few days ago. We caught a few fish on bead head peacock leeches, but nothing on dries even tho’ hoppers and trico spinners were abundant. The fish just were not interested in coming up. A big reason why was that weeds were breaking apart in the river. When this happens, life forms are released from them to drift in the current. All fish need to do to feed is hang out and grab drifting life forms as they go by. It takes minimum effort for them to respond in this manner, so no wonder those that we caught were in great shape.