Henry's Fork Report - October 5, 2023

Henry’s Fork Streamflows

Island Park Dam:  285 cfs

Ashton Dam:  1000 cfs

St. Anthony:  1230 cfs

Fall River:  555 cfs

The Henry’s Fork has been fishing well for those who look for fishing opportunities relative to the weather and flows.  Weather has been day to day, with temperatures quite a bit more fair than normal for the date, and fishing has been reflecting that in the absence of cloud cover and scuzzy weather.  Typically hatches at this time of year are regular regardless of weather, and more intense when clouds are in the sky.  This year, hatches are still weather dependent at this time, so keep an eye on the immediate forecast.  We have some cooler temps in the short term and warmer weather in the long term.  Flows have dropped considerably out of Island Park Dam in order to store water to secure winter flows.  Expect more exposed weeds in the system and water temps to adjust more rapidly to reflect current conditions.

Box Canyon

It’s a bumpy and slow float trip down the Box Canyon these days, but well worth the effort if you have gel coat to spare on your driftboats.  Walking your boat through some of the more shallow sections will save some wear and tear on your watercraft.  Low flows tend to concentrate fish in the canyon and make them more accessible to standard rigs, also allowing anglers to use less weight to get their flies in front of trout.  Flies selections should generally reflect the smaller insects that are actively hatching:  baetis and pseudos in particular.  We are liking PTs, R/L Tactical Pts, Micro Mays, Rednecks and Cocktail nymphs in 16-20, red and brown Zebra Midges 14-20, Black Zebra Midges 18-20, Rubberlegs stonefly nymphs 10-12, and your most trusty perdigons (Olive Hot Spots, Jake’s SH, Frenchies, and Jig Napoleons 16-20) will result in some hookups when fished well.  Dry/Droppers, indicator nymph rigs, and streamer set ups are all on the menu as good options at this point.

Railroad Ranch

Expect to find trout more concentrated into zones with holding water and a somewhat regular flow of insects.  Baetis, Pseudos and Mahoganies are the primary insects on the menu, spinner falls in the mornings may help find some regularly rising trout, but the real feeding activity revolves around the mahoganies for the day.  In the upper Ranch, clouds will help considerably and in the lower Ranch mahoganies are present most days but in lesser number when the sun is bright in the sky.  Weed beds are more exposed than they’ve been all year, use them to your advantage as they will help to hide your wake and often allow anglers to get much closer to their targets.  Upstream casting can be a real advantage, don’t overlook that angle when the currents are tricky.  Our Ranch boxes are stocked with a good variety of small spinners (Harrop’s Paraspinner, CDC Biot Spinner and the Copenhaver Spinner are all good bets in olive and cream in 16-20), CDC Biot Dun, Thorax Dun and Captive Duns 14-16 are a good start for Mahoganies, an unweighted pheasant tail can be a handy fly when greaselined in the film on a tricky trout.  Baetis patterns are also essential, we like the Sparkle Flag Dun, MFC Hi Vis Baetis, Bucky’s Upright Baetis 16-20 are good choices.  5X is the standard, 6X can be a valuable add when working a leader shy trout.

Canyon Country

The canyons of the Fork are low and good sections to fish as they are relatively weedless when compared to the upper and lower river.  At current flows, these are all day endeavors, so bring plenty of layers and a pre-noon start at the boat ramp is a good idea.  Dry/Dropper rigs are still the primary choice, try a rubberlegs or a large (#12-14) perdigon under a purple Chubby or your other favorite high-floating and high-visibility dry fly is a great place to start.  Streamers are a good option as well in the white water or when cloud cover is present.

Warm River to Ashton

Still a solid choice for a good day’s trout fishing, this section has it all; streamer fishing, indicator nymphing, and dry/dropper opportunities are all present, and it’s fun to spend the day in here switching between the rigs to enjoy a variety of fishing techniques and water types.  Nymph selections should be similar to those recommended for the Box Canyon, Streamers can be fished on floating lines or sink tips, now is a good time of year to experiment with different approaches, and you may find some trout sipping on baetis in some of the quiet corners and rock piles along the way.

Below Ashton Reservoir

The lower river is still providing anglers with some good fishing, but the quality of the day is very dependent on weather conditions.  Overcast days will bring more confidence and opportunity and sunny days can be slim pickings.  Generally we are streamer fishing or nymphing in the mornings and hoping for baetis hatches in the afternoons.  Keep an eye out for sneaky rise forms, as they are easy to miss this time of year.  Dropper selection should reflect the small insects that are hatching, and streamer selections are anybody’s best guess, we usually start with olives and blacks, but some flash can go a long way when natural colors aren’t working.

Get out there and have some fun, and enjoy these beautiful autumn days!