Henry's Fork Report - May 29, 2025
Henry’s Fork Streamflows
Island Park Dam: 479 cfs
Ashton Dam: 1440 cfs
St. Anthony: 2470 cfs
Fall River: 2060 cfs
As we near the final days of May, we are seeing some of the most beautiful days of the year, verdant lowlands with green grass and blooming wildflowers provide the foreground for a vista with snow-capped mountains and partly cloudy conditions. If you don’t have enough drama in your life, you’re bound to find it in the scenery these days! Water conditions are good throughout the system for the time being, we’d like to have a bit more water in the river but the system is generally fishable throughout its length with water temps and quality in good shape. Warmer than usual weather makes it feel like everything is a week early, with Mule’s Ears and Camas wildflowers in the high country and lilacs in the low country already coming to bloom before the end of May. Expect hatches to follow this trend, and begin to show up a bit earlier than we typically anticipate. Salmonflies are still around, spotty but present throughout the system. Some golden stones are flying about, a few March browns still hanging on, caddis on the uptick, and carpenter ants throughout the canyons and high country. We are coming into the time of year that warrants a well-stocked fly box for successful days on the Henry’s Fork.
Box Canyon
At current flows of under 500 cfs, expect a nice ride with some good bumps when navigating the canyon. Trout will generally be more concentrated into deeper holding water, but the presence of salmonflies can lure them into the shallows as well. Still some salmonflies around, but they will be on the wane, especially with the cooler weather in the forecast after the weekend. Dries, Dry/Droppers, and Indicator Nymph rigs are all effective at these flows. Salmonflies make for a good dry fly choice, but keep an eye out for spotty trout eating caddis in the week to come. Nymphs should reflect caddis, baetis, March Browns, stoneflies, PMDs and midges. We like the following: R/L Tactical PTs, PTs, Hare/Copper, HP Caddis Pupa, Split Backs, Tung Bruised PMDs, Olive Hot Spots, Rednecks #14-18, Zebra Midges in red and black #14-18, Rubberlegs #8-10, BSA Jig Rubberlegs #8-10, and 101 Stones #8-12. The usual suspects in the perdigon department will do the trick as well: Spanish Bullets, Bullet Quills, Red Jig Napoleons. At these flows, split shot will not always be necessary, be prepared to change your weight situation depending on the water you’re fishing, often a tungsten nymph or two will do the trick and keep you off of the rocks.
Railroad Ranch
Closed until June 15th
Canyon Country
The canyons have seen some traffic and some action this past week, with salmonflies having been present most of the last week. There are still bugs around from Riverside CG downstream to Warm River, but they seem to be on the wane, we expect this to fade away after the cool weather next week. In the meantime, lots of fun to be had down there with dry flies, dry/droppers and streamers. It’s pretty hard to beat a Chubby Chernobyl with a rubberlegs hanging 30-36” down in this water. Consider a fast-sinking bead head if bites are slim on the rubberlegs. Low flows make for a bumpy ride, but also for more fishable water. Carpenter Ants are flying around en masse and make for a fun fly selection if things slow down or they stop eating your salmonfly imitations! As ever, solid oarsmanship is a must and an inflatable raft is highly recommended for these sections.
Warm River to Ashton
There are still a few salmonflies around, but we expect the game to shift to a little more focus on nymphs over the course of the coming week. Nymph selection should mirror that of the Box Canyon, while dries can range: salmonflies, golden stones, caddis, March Browns, and PMDs can all be present this week. This is a fun time of year in this section, most years these next weeks are characterized by fewer numbers of fish but better quality in the catches.
Below Ashton Reservoir
The lower Henry’s Fork has seen its peak salmonfly activity, but there may be spotty hatches present over the weekend. Keep an eye out for a slow increase in golden stones as we move into the next weeks. This next week should see caddis activity with a possibility of PMDs coming into play, at these flows angler should keep a keen eye out for rising trout opportunities. Dry/dropper rigs will suffice for nymphing rigs, generally, but angler should be prepared to use indicators and deeper presentations during slower periods. Henry’s Fork Salmonfly and Golden Stone patterns, Chubby Chernobyls, Iron X Caddis, Spotlight Caddis, Bubble Back Caddis, PMD Comparaduns, and PMD Paraspinners #14-16 will get you started in the right direction. For below the surface, Rubberlegs #6-10, Tung Bruised PMDs, red Jig Napoleons, Hare/Coppers, HP Caddis Pupa, Zebra Midges and R/L Tactical PTs #14-16 will cover you in most scenarios.
Good luck out there, and have fun!
