Henry's Fork Report - July 17, 2025

Henry’s Fork Streamflows

Island Park Dam:  1630 cfs

Ashton Dam:  2160 cfs

St. Anthony:  1330 cfs

Fall River:  217 cfs

High flows and beautiful days abound in Henry’s Fork country these days.  These are great days to be outside and enjoying the great outdoors, these conditions make for some great fishing in some reaches and tough days in others.  Discerning dry fly anglers may want to consider checking out our other fishing reports for news on some great opportunities in the Greater Yellowstone, while streamer and nymph anglers will find some terrific fishing with these high flows.

Box Canyon

This is a good option on most days and the Box is putting out some fun fishing for subsurface anglers.  At these flows, this is a good choice for a quick streamer or dry/dropper run as well as a full day’s destination for those wanting to take their time and work the water.  The presence of golden stones lends itself to running a large dry fly at times, but indicator nymphing will be the technique of choice here for the all day angler.  We like a rig that has at least 5-6’ from indicator to first fly, the addition of BB and/or B split shot will assist in getting those flies down in the deeper, faster runs.  Adjust your weight for the water you’re fishing and set the hook at the slightest of hesitations.  We like the following nymphs down there:  Rubberlegs stonefly nymphs #6-12, SJW #10-12, Bouface Leeches #10, Hare’s Ear SHs, HP Caddis Pupas, Split Case PMDs, R/L Tactical Pts, Tungsten PTs, Rednecks #14-16.  Your favorite perdigons will work as well:  Olive Hot Spots, Duracells, Spanish Bullets, Bullet Quills, PMD Bombs, Jig Napoleons, Frenchies #14-18, and Black Daggers #16-18.  For streamers, we like fast-sinking flies like the BFE in olive and black and the BSA Bouface Leech #6.  This is a good time of year for a Copper Zonker as well, whether you’re stripping it or fishing it under an indicator.

Railroad Ranch

Slim pickins is the name of the game down here at the moment.  There are bugs around but not lots of targets, we expect these conditions to prevail until flows begin to decrease near the end of the month.  That said, a walk in the Railroad Ranch with a fly rod is always worth a try and one never knows what they might find.  You’ll want to be traveling with a fly box armed with various imitations of PMDs, Caddis, Flav spinners, Gray Drake duns, grasshoppers, beetles and ants.  If you find a rise, be prepared to get a shot out quickly and cover the area, you might spend all day waiting for another.  These trout are happy and healthy in these high flows, just not frequently looking to the surface for their food at the moment, so if you can locate one be sure to cover the area.  More than one rise in a short amount of time indicates a trout feeding on spinners or caddis, while a one time rise might indicate a Gray Drake or terrestrial diner.  Use the force!

Canyon Country

These canyon sections of the Henry’s Fork are whitewater adventures at the moment, lots of splashy fun with good dry/dropper or streamer fishing in a beautiful wilderness setting.  We are rolling with dry/dropper rigs, a rubberlegs or fast-sinking beadhead hung below a high viz Chubby Chernobyl is a great starter.  If you’re able to stop and work the water over, you might consider keeping an indicator rig handy to be a bit more thorough.  Streamer fishing is a solid bet at these flows, while trout often require lower light conditions to respond to streamers in the mid-summer, white water can have the same effect.  We like olive and black options, and a Copper or Olive Zonker is a good choice as well.  Weather sneaks up quickly on you in these canyons and afternoon thundershowers have been fairly common, so bring rain gear and be prepared!  Solid oarsmanship and an inflatable raft are musts down here.

Warm River to Ashton

This has been a fun piece of water lately with these high flows.  Good action on small and medium-sized fish with the occasional chance at something larger.  The banks have good depth and are holding some quality trout as well as the deeper transitions and pools.  Dry/dropper or streamer rigs are useful on the banks, while indicator rigs will be more productive in the deeper waters.  Fly selection can mirror that of the Box Canyon.

Below Ashton Reservoir

High flows above Chester Dam and lower flows below.  Most opportunity will be found in the higher water reach, but will be limited to mornings and evenings for occasional chances.  There’s not a lot of draw for anglers to these reaches just yet, but an early morning streamer run could be worth it for those so inclined to look for a little quality and not much quantity. 

Get out there and enjoy!