Henry's Fork Report - July 3, 2025

Henry’s Fork Streamflows

Island Park Dam:  1420 cfs

Ashton Dam:  2100 cfs

St. Anthony:  1110 cfs

Fall River:  267 cfs

It’s July on the Henry’s Fork during one of the toughest water years we’ve seen in some time.  This means a lot of different things, many of them somewhat counter intuitive, with fishing opportunities that arise because of mid-summer’s inverse relationship with low incoming flows and high outgoing.  River-wide, flows are relatively high due to irrigation demand at all locations downstream of Island Park Reservoir and upstream of Chester Dam.  No one out there is more happy about this than the resident trout of the Henry’s Fork, these high flows give them a little more water to hide in, make available lots of subsurface food, and keep them somewhat fresh for when the flows begin to drop as demand subsides hopefully later this month.

Box Canyon

At current flows, the Box is a breeze to get through and can be used for an all day affair or a short half day excursion.  Having high water in the mid-summer gives anglers the opportunity to fish larger flies and brings streamer fishing into play during low light periods.  Golden stoneflies are still around and a midday dry fly run is not out of the question.  Generally, indicator rigs are the choice down here at the moment, and anglers should be prepared with B and BB split shot to assist in getting their rigs down to the fish.  Rubberlegs nymphs #8-10 are back in play, and a variety of leech patterns can bring success, we generally like black, gray or claret colors for these.  Other nymphs you’ll want to keep on hand are:  PTs, R/L Tactical PTs, HP Caddis Pupas, Hare/Coppers, Rednecks sizes 14-16, red and black Zebra Midges #14-18.  Fast-sinking perdigons are an excellent choice as well, we like the following:  Olive Hot Spot, Frenchie, red Jig Napoleon, Duracells, PMD Tung Bomb, Spanish Bullet, Bullet Quill #14-18.  Be prepared to adjust your split shot for the water you’re fishing, taking some time to stop and work the water can yield results on an otherwise slow float through.  Streamer runs in the mornings and evenings can be fun as well, we wouldn’t go without a few BFEs (Best Fly Ever) #4-8, BSA Bouface Leeches #6-10, both in olive and black. 

Railroad Ranch

While the current flow situation isn’t ideal for finding lots of rising trout in the Ranch, there are some to be found, we’re getting mixed reports from anglers.  Most are having a hard time finding many targets but those who dig in and look hard are finding some trout to play with out there.  During these times of volatile and high flows, remember that springs offer not only thermal benefits to the river but also more stable conditions and challenging trout.  Anglers should be sure to have imitations in several life stages of Flavs, PMDs, Caddis, Gray Drakes, as well as some terrestrial patterns that imitate hoppers, ants and beetles.  There are some Gray Drake and Flav/PMD spinners around in the mornings, it’s always worth a morning walk to see what may come up.  Hot and sunny afternoons won’t yield too much in the way of rising targets but a little luck combined with your favorite terrestrial may just bring someone around to play.

Canyon Country

These sections offer whitewater fun with some decent action with dry/droppers.  At high flows, there is quite a bit of water that is difficult to reach, but there will be trout near the transitions and drop offs as well as nearer the shore than usual.  Streamers can be a great way to look for a larger trout at this time of year and some of the residents lose their light sensitivity when in white water zones so they can be fished through the midday periods.  We like BFEs and BSA Boufaces in here in olive and black, but always have a Sparkle Minnow handy as well as our favorite white streamers handy, Zonkers are a good choice as well.

Warm River to Ashton

This fun piece of water is one of the most stable experiences on the Henry’s Fork and will continue to put smiles on anglers’ faces regardless of flows.  All skill levels can find something to do in here, with indicator nymphing, dry/dropping, streamer fishing and some dry fly fishing all producing results.  Greatest successes will come from indicator rigs but more quality specimens can be sought out with large single dry flies or streamers.  As in the Box Canyon, Rubberlegs nymphs and leech patterns can be very effective here when fished under an indicator.  Same fly recommendations as for the Box Canyon, but be sure to throw in some brown Zebra Midges #14-16 in addition.

Below Ashton Reservoir

The lower river is still fishable above the Chester Dam, but anglers will have to use their best judgment regarding rigs.  Morning and evening streamer runs can be entertaining, indicator nymphing will produce a few hookups, and there’s still a chance that a golden stone or hopper patter fished blind will produce a few nice trout along the way.  Fishing has slowed way down on these waters, and anglers should be mindful of water temps, especially on the low flow waters below Chester Dam.  We’re close to leaving these sections alone for the next few weeks.

Good luck out there!