Henry's Fork Report - June 12, 2025
Henry’s Fork Streamflows
Island Park Dam: 473 cfs
Ashton Dam: 1190 cfs
St. Anthony: 1130 cfs
Fall River: 1040 cfs
This is shaping up to be a difficult year for water managers with very low natural streamflows and rapid snowmelt that seems to be going straight into the ground rather than into the rivers. However, water quality in the Henry’s Fork is terrific at the moment and is likely to be good for the coming week. In the short term, the final blast of snowmelt should allow for some great fishing in the coming week or two, but it’s hard to say much beyond that as daily weather will be the deciding factor. Green Drakes, Golden Stones, Caddis, and PMDs are all in the system, Flavs are on the horizon but not yet making a real presence. Flows are low throughout the river, but irrigation demand is on the rise and angler should expect some increases in flow through this next week.
Box Canyon
The Box is a bumpy ride but is putting smiles on anglers’ faces, fishing is good in there and you’ll find trout concentrated in the holding water with more depth. Anglers will do well to stay locked into the leg braces but should be ready to set the hook on the slightest of movements on their indicators or dry flies when nymphs are at work below. Trout are feeding, but they won’t move as far for smaller food, takes will be subtle. Small flies are the name of the game in here, with a strong favoring of nymphs in sizes 16-20. Indicator nymphing rigs are the standard choice, but there is plenty of room for dry/droppers. Either way, the focus is generally on subsurface fishing. We are liking flies that generally imitate stoneflies, PMDs, caddis, and Flavs. In our boxes you’ll find plenty of PTs, R/L Tactical PTs #12-18, Split Backs, HP Caddis Pupa, Hare/Coppers #14-18, Zebra Midges in red and black #16-18, as well as the odd Rubberlegs, Two Bit Hooker, or 101 stonefly nymph in #8-12. Perdigons are a good choice as well and we like the Olive Hot Spot, red Jig Napoleon, Frenchie, PMD Tung Bomb, and the Duracell #14-18.
Railroad Ranch
Closed until June 15th, this Sunday marks the long awaited opener of the waters within Harriman State Park. As far as opening days go, this one has a high likelihood of being a fun one with some decent hatches and (hopefully) water conditions. Caddis and PMDs should be on the menu and Green Drakes are a distinct possibility. A close eye should be kept on flows out of Island Park Dam as drastic increases due to irrigation demand may affect fishing. This is one of the great days in the ecosystem of flyfishing in the United States, a grand celebration of a fabled piece of water that encourages anglers to take their angling to a higher level. Large, technical trout that are pursuable through their discernable riseforms and footprints on the water, requiring fly changes and a thoughtful approach. This is not only a piece of water that rewards skill but also one that gifts those who are willing to participate and enjoy the strong element of luck in the act of fishing. Anglers of all skill levels are invited to join in the camaraderie of the opening day of the Ranch. On the night of June 14th, Trouthunter will host its annual “Ranch Opener Party”, one of the best parties in the world of flyfishing, join them in a celebration of the new year on a piece of water that is celebrated worldwide for its unique properties and the pursuit of flyfishing as a hobby, way of life and everything in between. Anglers will do well to arrive with a well-stocked fly box that includes representations of Caddis, PMDs, Green Drakes, the odd Golden Stonefly and a variety of terrestrials including beetles and ants. The upper river has a decent population of trout this year and we hope that you’ll find some worthy targets on the opener and in the days that follow!
Canyon Country
These wilderness sections of the Henry’s Fork will provide anglers with a worthwhile experience if they’re looking for solitude and good trout fishing. Low flies combined with a high fish per mile count present the opportunity for a day’s fishing without crowds and with decent action on small trout with some larger surprises sprinkled in. Dry/dropper rigs are the choice here, usually a Chubby Chernobyl variant with a rubberlegs or fast-sinking beadhead are all one needs to have some fun down here. Streamers are always an option for those inclined. Solid oarsmanship a must and an inflatable raft highly recommended.
Warm River to Ashton
Good action on small to medium sized fish is the name of the game here, though there are usually some nice trout taken along the way. This week could see decent caddis, PMD and possibly Green Drakes or Flav activity, so be prepared to slow it down if you see fish rising. Generally we are dry/dropper or indicator nymph fishing here these days, but a keen eye for rising fish is key in the coming week. Fly selections should mirror those for the Box Canyon with an addition of small black leeches.
Below Ashton Reservoir
Green Drakes are making their presence known lately and should continue through this week, likely diminishing after the weekend. PMDs are sparse but present, caddis have been the dominant insect overall. On the horizon are Flavs, but we haven’t seen many yet. The river is fishable all the way to the confluence with the Snake, so there are many floating options for those so inclined as to explore the lower reaches. Dry flies should include emerger, adult and spinner imitations of all of the aforementioned insects as well as Golden Stone dry flies. Nymph selections should be representative of these insects as well. This is a place to arrive with a well-stocked fly box.
The river is low and easily wade-able. Boaters should be considerate of wading anglers and be willing to ask how best to pass them without disturbing their fishing. Wade anglers should be aware that boating options are difficult without much water and be willing to indicate where the best passage will be so as to minimize the effect on their fishing. It’s Row vs. Wade out there, do your best to be considerate of other anglers and share the water as best as you’re able.
In short, none of us know what’s in store for the next month, but fishing and water conditions are good for the week to come, so enjoy and have some fun out there!
