Henry's Fork Report - August 1, 2024

Henry’s Fork Streamflows

Island Park Dam:  949 cfs

Ashton Dam:  1630 cfs

St. Anthony:  873 cfs

Fall River:   329 cfs

The Henry’s Fork has turned over a new leaf in the past couple of days, coming down to a reasonable flow after weeks of high water out of Island Park dam.  Flows were significantly reduced this last Tuesday by almost 350 cfs, it’s our hope that this will result in a slight increase in hatches and an increase in the number of trout looking to the surface for their food.  The hot weather of July has found a brief reprieve this last week, with afternoon thundershowers bringing the air temps down. There’s more hot weather to come, but we are starting to feel the cool mornings that are the result of increasingly longer nights as we approach August and late summer.  Water quality remains good with

Box Canyon

The reduction in flows will make the Box Canyon a bit more bumpy  an endeavor but anglers will find it easier to read and fish the faster water more effectively.  Flows are still comfortably high enough to make this an all day or half day journey.  Anglers can expect to reduce the weight on their indicator nymphing rigs, a single BB shot should do the trick in most cases, further reducing weight in the shallow reaches will be good approach.  There are still decent numbers of golden stones flying around the canyon, but we expect this to be on the decrease in the week to come.  Indicator nymphing rigs are the standard choice for all day anglers here, but dry/droppers, dry flies, and streamers are all a fair bet.  For nymphs, we like PTs, R/L Tactical PTs, Split Cases, CDC Jig PTs, Red and Brown Zebra Midges 14-18; Two Bit Goldens, 101 Stones, Rubberlegs #6-10.  Perdigons like the Spanish Bullet, Bullet Quill, Olive Hot Spot, Frenchies, PMD Bombs, and Red Jig Napoleons  14-18 are all good choices as well.  We generally like heavy streamers on floating lines in there:  Olive/Black, White, and Black BFEs, Olive and White Bouface Leeches, and Olive, White and Copper Zonkers are all good choices.

Railroad Ranch

After a couple of weeks of fairly slow fishing and minimal bug activity, we are hoping to see a slight increase in the number of fish willing to look to the surface for food.  The best activity has been found near areas of spring influence, with fair PMD, caddis and midge hatches.  We expect to see this continue, but also expect to see some more opportunity throughout the Ranch with small spinners in the morning sessions.  Terrestrial activity should be picking up in the week to come as well as the grasshoppers increase in both size and number.  A few sightings of flying ants these past days lends an additional degree of hope to the Ranch angler for the coming timeframe.  We are entering a period of the summer where riseforms can be sparse but fishing can be excellent.  Anglers will do well to observe patiently to determine whether their target is on the move or stationary, and put a fly into play quickly when the shot presents itself.  Fly boxes should be well stocked with a variety of spinners 14-18, PMD patterns in duns and emergers, with a strong focus on the emerger versions, we like Harrop’s CDC Biot Dun, CDC Thorax Dun, Heames’ PMD Klinkhammer, and Halfbacks.  HF Caddis in both tan and dark brown 14-18, Gray Drake hackled spinners, a handful of hoppers and ants.  For ants, we like to have small black winged ants like the Shimazaki in 16-20 and honey ants like the Heames Honey Ant in 14-16.

Canyon Country

The remote canyon sections of the Fork will respond to the lower flows favorably, these sections are characterized by fast, roiling water that will be more easily penetrated by flies at current flows.  Dry/dropper rigs are the main choice here, but streamers are an excellent option for those who prefer to target fewer, but larger trout.  Copper Zonkers, Black/Olive/White BFEs, and Bouface Leeches are all good bets, these are best fished on a floating line with 1X tippet.

Warm River to Ashton

This time of year is a great time to enjoy this section, as it provides anglers of all skill levels an opportunity at a fun day’s fishing.  Indicator nymphing rigs can provide good action throughout the day on smaller fish, with a few larger surprises mixed in there.  Dry/dropper rigs fished in the transitions can be effective as well, with an occasional brown trout willing to look to the surface to take in a grasshopper pattern.  Streamer anglers will find some willing trout in the morning hours, often a larger fish or two will give it up and make it worth the effort.  Afternoon hours, in the absence of thundershowers, will generally favor the nymphing crowd.  The same flies that are being recommended for the Box Canyon will work wonders down here.

Below Ashton Dam

There is a little morning opportunity for anglers down here, but with lower flows and hot weather on the horizon, anglers should be looking for alternatives after the clock strikes noon.  It’s a good idea to keep a close eye on water temps down here, usually they will hit 70 degrees by midday and then it’s time to go somewhere else.