Fishing Report - September 26, 2025

Upper Henrys Fork:

With Fall here and cooler evening temperatures, we are finally seeing some better fishing in the upper river. The river is very low and has cleared up. I would recommend wading in the Box Canyon rather than floating it, unless you like to smash your boat all to pieces. The nymphing and streamers have been working. Fish in the deeper pools, as that’s where the fish are forced to be. Small zebra midges in black, olive, and tan sizes 18 and 20. Don’t be afraid to drag a streamer through those pools either. I love a copper zonker size 6, or an olive and copper Lil’ Kim in size 6. 

The upper and lower Harriman State Park are finally fishing decent. We are seeing some decent Mahogany Dun hatches. The fish are very spooky with the shallow water, but if you use a long leader, you can get it done. I love the Mahogany No hackle in size 18. I figure if they won’t eat a no-hackle, I’d best sit on the bank and listen to elk bugle. 

Lower Henrys Fork:

With cooler nighttime temperatures, the lower river is fishing well. Even with the bright sunny days, we are still seeing some Mahogany duns. The fish are pretty spooky with the low water, but they can still be fooled with the right cast. There are also plenty of hoppers jumping around, so if nothing is rising, you can sometimes get a big brown on a hopper. It can also be effective to hang a small 18-inch 18 tan zebra under a hopper for some more action. The Browns also get pretty aggressive as spawning is just around the corner, so if you like stripping a streamer, I’d highly recommend it!

South Fork of the Snake: 

Streamer fishing has likely been the best method of going about things on the South Fork, with deeper nymph rigs and hoppers/beetles also being productive. I like the Thunder Thighs Hopper with a size 12 Duracell nymph dropper. There has also been some pretty great fishing on mahogany duns. They aren’t everywhere, but some little pockets of rising fish can make your day. 

Madison River: 

Terrestrials will still be the name of the game on the Madison. Our favorite flies for this area will be hoppers and beetles, with a smaller dry fly trailing (ants, parachute Adams, or even a good old Griffith’s gnat). The specific patterns I like are a Green Machine dropping a Hi Vis foam Beetle. I will never write a fishing report in September without mentioning streamers. If there is a river with brown trout in September, throw a streamer and you might catch a monster!

Teton River:

The Teton is running on the low end, 361cfs near St Anthony, but cooler weather is helping out on the water temperature side of things. Fishing continues to be productive around Driggs with both wade fishing and float opportunities. The upper Teton River near Driggs and Tetonia is the best option for dry flies. There have been some great fish caught on Mahogany Duns, Grey Drakes, and Ants, beetles, and, of course, hoppers. And as always, drag that streamer through the deep water. Rumor has it that the Idaho Fish and Game shocked up a 30-inch hybrid. 

Yellowstone National Park:

The Park is a fantastic place to go this time of year. Pick your river and go. I love the Madison in the Park. You can get fish on Hoppers and ants, but if I’m going, I’m throwing a streamer. I love those big browns moving up out of Hebgen Lake. As always, be mindful of bears and take bear spray. Grizzlies are active in all areas of the park, and especially during the Fall. 

Lakes:

Henry's Lake- The fish have started moving out of the deep water and cruising on the shoreline. Stripping small leeches and woolly buggers is a good way to target these cruising fish. Cocktail nymphs, chironomids, and flashback pheasant tails also do well under a dry or indicator. 

Hebgen- Hebgen has started to slow down, the gulpers have appeared to have turned off for the most part, and we have seen evidence of the fish staging up in preparation for the fall spawn. You can find these fish stacked, ready to move up the Madison. We recommend focusing on the rivers (the Madison and Grayling Creek) this time of year, though you can still find fish within the lake.