Henry’s Fork Streamflows
Island Park Dam: 326 cfs
Ashton Dam: 1020 cfs
St. Anthony: 1230 cfs
Fall River: 509 cfs
The Henry’s Fork has been a day to day fishing endeavor that depends greatly on the weather. Our steady hatches of fall baetis, that persist regardless of clouds or sun haven’t quite hit their stride as water temps are still not yet cold enough to produce those consistent bugs that we all hope for in October. However, good hatches of baetis are out there when there are clouds in the sky and there are still a few mahogany duns hatching when the weather is right. On sunny days, anglers will do well to stick to the faster waters of the canyons or above Ashton Reservoir. Cloudy days will bring good opportunity on the Ranch and lower river. Flows have been relatively constant throughout the system, with turbidity at average for the date. This coming week we expect to see a reduction in flows out of Island Park Reservoir to about 200 cfs, this is being done in an effort to get more water in the reservoir and secure higher winter flows for the benefit of the fishery in the coming years.
At these flows, the Box is a fishy endeavor and a bumpy ride. It’s going to get bumpier once flows begin to drop on Monday, but the fishing should hold up well. Indicator nymphing is the standard choice of rigs, and will be even more so in the coming weeks. Adjust your weight to the depth of water your fishing as well as the distance of your indicator to your first fly. At times, no weight will be needed at all, just the weight of the flies you’re fishing will do the trick. We are liking small nymphs in here these days, suggestive of baetis and midges: PTs, Cocktail Nymphs, R/L Tactical PTs, Frenchies, and Rednecks 18-20, Zebra Midges in red, brown and black 18-20, Rubberlegs stonefly nymphs 10-12, Juju Baetis 18-20 and your favorite perdigons (Jake’s SH, Olive Hot Spot, Jig Napoleons 16-20) will all do the trick.
Weeds are an issue, so use them to your advantage, they break your wake when wading and can allow you to get closer to your targets. Landing a big trout when the weeds are around is 50/50, but the real reward is bringing them to your fly and getting them hooked up. Baetis are the name of the game, Pseudos are around on a daily basis with some fish eating them, but baetis and a few mahoganies will bring up the larger fish in better numbers. Cloudy days will be better than sunny ones, but a sunny morning is still worth taking your rod for a walk. We’re liking Copenhaver and Harrop’s spinners 18-22, Flag Duns, MFC’s Hi Vis spinner, Comparaduns and Bucky’s Upright Baetis in 16-20. For mahoganies thorax duns, CDC Biot Duns, and Captive Duns 16-18 are all essential.
Not too many people foraying into the more remote canyon sections this time of year, though they make for beautiful floats, the colder temperatures of fall and the fewer hours of daylight in the canyons bring with them a shorter window of fishing opportunity. If you do venture in here, bring plenty of layers in case the weather turns on you and your A-Game as an oarsman. This is rubber raft country for sure.
Warm River to Ashton
This is one of the more consistent sections of the Henry’s Fork at this time of year and makes for a good choice for anyone who isn’t sure where they want to target their efforts in a variety of weather conditions. There is enough diversity in water type down here that indicator rigs, dry flies, and streamers will all produce results, just be willing to adapt your technique to the day you’re given. Nymph selection will be about the same as the Box Canyon recommendations. Streamers selection leave a lot of room for creativity, and dry flies will most often represent baetis.
Below Ashton Reservoir
Fishing on the lower river has been very day to day and highly dependent on the weather. Cloudy days will give more opportunity than sunny ones. Indicator nymphing or streamer fishing in the mornings with a few hours of dry fly fishing in the afternoons is the hope. Small nymphs reflective of baetis are a solid choice and low profile streamers that shed weeds are a wise choice down there, we like olive, black and white to start. Dry flies will be similar to those recommended for the ranch.
Good luck out there!