Henry's Fork Report - August 17, 2023

Henry’s Fork Streamflows

Island Park Dam:  594 cfs

Ashton Dam:  1330 cfs

St. Anthony:  849 cfs

Fall River:  324 cfs

This past week has kept anglers on the Henry’s Fork smiling and finding just enough activity to keep them engaged most of the day.  What started with cold mornings that foreshadowed the pending fall has progressed into a summertime groove with days quickly warming hot afternoons.  Water clarity has been excellent these past days.  We expect to see some warm days ahead followed by a little cloud cover and chance of showers this weekend.  Hatches are slim at this time, but there are enough bugs around to keep things interesting.  More flow fluctuations are expected, but nothing too major in the near future.

Box Canyon

The Box is steadily flowing at around 600 cfs and at this flow there is some great fishing to be found, the water is easily read and worked, and there are just enough rocks poking out to keep an oarsman busy.  Though indicator nymph rigs reign supreme, dry/droppers and streamers in the low light are also good options.  If fishing under an indicator, bring some B shot for the deeper water and take it off for the in between sections.  Dry/droppers can be effective throughout, but are most successful if treated as a shallow nymphing rig at this time.  Match the rig to the water you’re fishing, trout are still fairly spread out, so there is opportunity throughout the canyon.  Hatches are sparse, so think midges, small PMDs and the occasional caddis.  Our best nymphs lately have been reflecting these insects.   PTs, R/L Tactical PTs, Rednecks 14-18, SH Hare’s Ear, Olive Hungarian Partidge Caddis Pupa 14-16, Zebra Midges in red and brown 14-18, black Zebra Midges in 18-20, Rubberlegs and 101 stonefly nymphs 8-12, and your favorite perdigons (Olive Hot Spot, Bullet Quill, red Jig Napoleons, Frenchies, CDC France, and Jake’s SH) will all help to bring fish to the net.  If turbidity increases, try flies with a wrap of fluorescent around the collar, it doesn’t take much to create a hot spot trigger.

Railroad Ranch

Spinners are the name of the game out there, folks.  Play your spinner fall in the morning and hope it lasts all day, but know that it probably won’t.  Calm days will keep bugs around and on the water for longer periods, once the wind picks up, look for wind loaded banks and small slicks to find a few noses, otherwise, it’s time to pack it in.  Trico, PMD and Callibaetis spinners are the most consisten bugs but you’ll still find a few Flav spinners as well.  Flying ants are most certainly on the menu, there have been some around most days but not in great numbers for the most part.  Still, there are just enough that a good number of trout have a few of them in their bellies and are eager for another, not a bad idea to cover a difficult trout with the ant pattern of your choice.  PMDs can be found hatching when there are afternoon clouds and around springs.  Our Ranch boxes at the moment are well-stocked with:  rusty and cream Copenhaver spinners, Harrop Paraspinners, Profile spinners, and the like in 14-20.  CDC Biot Duns 16-20 make for a great knock down dun on a breezy afternoon, and a few emergent flies like the Last Chance Cripple, Heames PMD Klinkhammer, Captive Dun, and Halfback 14-18 are good to keep on hand.  An unweighted PT nymph can be useful to sight fish a trout that is feeding subsurface in shallow water as well.  For flying ants we like the Harrop Honey Ant, the Heames Honey Ant, and the Shimazaki Ant 14-18.  It pays to have a few hopper patterns around, hot weather in the forecast should increase the hoppertunity out there.  The odd caddis is bouncing around out there as well, so don’t leave that section of your flybox empty.  Be prepared to walk to find targets, there are fish rising out there, but not in great concentrations, so bring some water and be willing to hunt them out.

Canyon Country

The canyons of the Henry’s Fork always provide a welcome break from the heat of summer with their steep canyon walls and peripheral hours of shadow.  These are great days to take a journey through the wilderness and enjoy some of the more remote sections of the river.  Fishing varies from day to day, but most days provide anglers with enough action to make the endeavor a worthy one.  Dry/Droppers in the form of the classic Hopper/Dropper or endlessly successful “Chubberlegs” combo are typically the first choice, but if they won’t eat the big nymph, downsize to an oversized perdigon or quick-sinking varietal that represents a small stone, large mayfly nymph or caddis larva.  Streamers during the low light hours or in the whitest and most churned up bits of water can also produce larger surprises.  We like a BFE in olive or black and a Copper Zonker at this time of year.

Warm River to Ashton

Warm days in the forecast call for an earlier start than normal, with a plan for fishing to slow down in the heat of the day by 4 or 5pm.  Good action on smaller trout with some surprises mixed in can be found with indicator nymph rigs as well as dry/droppers.  Streamer purists will do well to focus on the early and later hours or periods with cloud cover.  Nymph selection should reflect that of the Box Canyon, but be sure to add some red Copper Johns 14-16, black and olive Bouface Leeches 10, and some Copper Zonkers that can be stripped or fished under the indicator.  Don’t forget your wide-brimmed hat and some sunblock!

Below Ashton Reservoir

Though some action has been found down here in the past weeks, with the hot weather in the forecast we will likely be focusing our efforts upstream of Ashton Reservoir.  A morning run may produce some activity but be sure to have another plan for the afternoon hours and keep an eye on water temps, when 70 degrees arrives, it’s time to go somewhere else, usually upriver.

Get out and enjoy summer while it’s still here, fall is right around the corner!